Search

Background: Acupuncture may improve motor function in patients with chronic hemiparetic stroke, yet the neural mechanisms underlying such an effect are unknown. As part of a sham-controlled, randomized clinical trial testing the efficacy of a 10-week acupuncture protocol in patients with chronic hemiparetic stroke, we examined the relationship between changes in function of the affected upper limb and brain activation using functional magnetic resonance imaging (fMRI). Methods: Seven (7) chronic hemiparetic stroke patients underwent fMRI and testing of function of the affected upper limb (spasticity and range-of-motion) before and after a 10-week period of verum (N � 4) or sham (N � 3) acupuncture. The correlation between changes in function of the affected upper limb and brain activation after treatment was tested across patients. Results: We found a significant positive correlation between changes in function of the affected upper limb (spasticity and range of motion) and activation in a region of the ipsilesional motor cortex. Patients treated with verum acupuncture showed a trend toward a greater maximum activation change in this motor cortical area as compared to those treated with sham acupuncture. Conclusions: Acupuncture may improve function of the affected upper limb in chronic hemiparetic stroke patients by increasing activity in the ipsilesional motor cortex.

Wayne PM, Krebs DE, Macklin EA, Schnyer R, Kaptchuk TJ, Parker SW, Scarborough DM, McGibbon CA, Schaechter JD, Stein J, Stason WB. Acupuncture for upper-extremity rehabilitation in chronic stroke: a randomized sham-controlled study. Objective To compare the effects of traditional Chinese acupuncture with sham acupuncture on upper-extremity (UE) function and quality of life (QOL) in patients with chronic hemiparesis from stroke. Design A prospective, sham-controlled, randomized controlled trial (RCT). Setting Patients recruited through a hospital stroke rehabilitation program. Participants Thirty-three subjects who incurred a stroke 0.8 to 24 years previously and had moderate to severe UE functional impairment. Interventions Active acupuncture tailored to traditional Chinese medicine diagnoses, including electroacupuncture, or sham acupuncture. Up to 20 treatment sessions (mean, 16.9) over a mean of 10.5 weeks. Main Outcome Measures UE motor function, spasticity, grip strength, range of motion (ROM), activities of daily living, QOL, and mood. All outcomes were measured at baseline and after treatment. Results Intention-to-treat (ITT) analyses found no statistically significant differences in outcomes between active and sham acupuncture groups. Analyses of protocol-compliant subjects revealed significant improvement in wrist spasticity ( P P P P =.09) and digit ROM ( P =.06). Conclusions Based on ITT analyses, we conclude that acupuncture does not improve UE function or QOL in patients with chronic stroke symptoms. However, gains in UE function observed in protocol-compliant subjects suggest traditional Chinese acupuncture may help patients with chronic stroke symptoms. These results must be interpreted cautiously because of small sample sizes and multiple, unadjusted, post hoc comparisons. A larger, more definitive RCT using a similar design is feasible and warranted.

Tai Chi (TC) is a comparatively new intervention for peripheral vestibular hypofunction, which is often treated with vestibular rehabilitation (VR). We compared gaze stability (GZS), whole-body stability (WBS) and footfall stability (FFS) during locomotion among 26 people with vestibulopathy (VSP), randomized into two treatment arms (13 TC and 13 VR). Each intervention program was offered for 10 weeks. GZS improved more for VR than for TC, but WBS (and FFS) improved more for TC than for VR. There was a significant relationship between changes in GZS and WBS for the VR subjects (r = 0.60, p = 0.01), but not for TC subjects. There was a significant relationship between changes in WBS and FFS for both VR (r = 0.65, p < 0.01) and TC (r = 0.58, p = 0.02) groups; the relationship disappeared in the VR but not the TC group when controlling for GZS. These findings suggest that VR and TC both benefit patients with VSP but via differing mechanisms. Moreover, these data are the first to test the assumption that improving gaze control among patients with VSP perforce improves postural stability: it does not. We conclude that GZS is most improved in those who receive VR, but that TC improves WBS and FFS without improving GZS, suggesting patients with VSP can rely on non-gaze related mechanisms to improve postural control.

Wayne PM, Krebs DE, Wolf SL, Gill-Body KM, Scarborough DM, McGibbon CA, Kaptchuk TJ, Parker SW. Can Tai Chi improve vestibulopathic postural control? Arch Phys Med Rehabil 2004;85:142-52. Objectives To evaluate the rationale and scientific support for Tai Chi as an intervention for vestibulopathy and to offer recommendations for future studies. Data sources A computer-aided search, including MEDLINE and Science Citation Index, to identify original Tai Chi studies published in English; relevant references cited in the retrieved articles were also included. Study selection A preliminary screening selected all randomized controlled trials (RCTs), non-RCTs, case-control studies, and case series that included Tai Chi as an intervention and had at least 1 outcome variable relevant to postural stability. Data extraction Authors critically reviewed studies and summarized study designs and outcomes in a summary table. Data synthesis Twenty-four Tai Chi studies met screening criteria. No studies specifically studying Tai Chi for vestibulopathy were found. Collectively, the 24 studies provide sometimes contradictory but generally supportive evidence that Tai Chi may have beneficial effects for balance and postural impairments, especially those associated with aging. Ten RCTs were found, of which 8 provide support that Tai Chi practiced alone, or in combination with other therapies, can reduce risk of falls, and/or impact factors associated with postural control, including improved balance and dynamic stability, increased musculoskeletal strength and flexibility, improved performance of activities of daily living (ADLs), reduced fear of falling, and general improvement in psychologic well-being. Studies using other designs support the results observed in RCTs. Conclusions At present, few data exist to support the contention that Tai Chi specifically targets the impairments, functional limitations, disability, and quality of life associated with peripheral vestibulopathy. There are, however, compelling reasons to further investigate Tai Chi for vestibulopathy, in part because Tai Chi appears useful for a variety of nonvestibulopathy etiologic balance disorders, and is safe. Especially needed are studies that integrate measures of balance relevant to ADLs with other psychologic and cognitive measures; these might help identify specific mechanisms whereby Tai Chi can remedy balance disorders.

Although vestibular rehabilitation (VR) is gaining popularity, few data support its utility in improving locomotor stability, and no good predictors exist of whom will benefit most.A double-blind, placebo-controlled randomized trial of vestibular rehabilitation was conducted at a large tertiary care hospital on 124 patients (59 +/- 18 years old) with unilateral (n = 51) or bilateral (n = 73) vestibular hypofunction, of whom 86 completed a 12-week intervention. Of these 86, 27 returned for long-term (1-year) follow-up testing. The primary outcome measure was locomotor stability.Group A (6 weeks of VR) significantly (P0.01) increased their gait velocity and stability compared with group B (6 weeks of strengthening exercise), but there was a smaller difference (P = 0.05) between groups at 12 weeks, when both had had VR; there were no group differences at 1 year. Of the 86 who completed the intervention, 52 (61%) had clear locomotor gains.VR is helpful for most patients in providing locomotor stability, but further work is needed to determine the factors that prevent VR from being effective for all patients with vestibulopathy.

Histological examination of the optic nerves of Alzheimer's disease (AD) patients has revealed a selective degeneration of large axon ganglion cells. This morphological abnormality raises the possibility of a selective impairment of broad-band channel visual function. To test this hypothesis, we administered visual psychophysical tests associated with either the color-opponent or the broad-band retinocortical channel to 14 AD patients and 29 elderly control subjects (ECS). In previous studies in monkeys, these tests had been sensitive to the effects of either parvocellular or magnocellular LGN lesions. In the present study, the color-opponent channel was assessed by tests of texture and color discrimination; the broad-band channel was assessed by tests of flicker and motion detection. Logistic regression analysis indicated that all tests collectively discriminated diagnostic groups at a borderline level of significance (p = 0.09). ANOVA also indicated a trend towards overall depressed function for AD patients on some capacities tested. Analyses comparing the prevalence of deficits in the AD and ECS groups showed that a significantly greater number of AD patients than ECS had deficits on texture discrimination, blue-violet discrimination, and 4.72°/s motion detection. No individual subject demonstrated a selective impairment of broad-band channel function. The visual deficits in AD did not resemble those caused by lesions of magnocellular LGN in monkeys, indicating that the visual impairment in AD is not a functional reflection of damage limited to the broad-band channel. Rather, the perceptual deficits we observed may be due to neuropathological changes in visual association cortices, particularly the ventral visual pathway, in which parvocellular as well as magnocellular capacities are represented. The deficits are found in a subset of AD patients, suggesting that they are not an obligatory correlate of mild to moderate AD but, instead, reflect individual differences in the distribution of neuropathological changes in visual cortices.

This report describes a battery of tests that is utilized by several clinical laboratories to investigate vestibular and balance function. The electronystagmogram evaluates eye movements, inner ear function, brainstem function and cerebellar function. Sinusoidal vertical axis rotation is a sensitive measure of horizontal semicircular canal function that is often complimentary to the caloric stimulation portion of the electronystagmogram. Visual-vestibular interaction rotation testing is designed to evaluate brainstem, cerebellar and oculomotor function. Dynamic posturography facilitates measurement of standing balance and permits a quantification of the role of proprioception, vision and the vestibular system in the maintenance of standing balance.

Twenty-one patients with postherpetic neuralgia of two- to 84-months duration participated in a double-blind, placebo-controlled study of oral acyclovir. Pain perception was assessed with the Melzack Pain Questionnaire at baseline and at two- to six-week intervals during the ensuing six months. Clinically significant pain reduction occurred in eight patients: four received acyclovir, and four received a placebo. Several treatment strategies have been advocated for relief of postherpetic neuralgia. Results of the present study demonstrate the need for a double-blind, placebo-controlled paradigm to substantiate the efficacy of new clinical approaches. The same caveat applies to the more common syndromes encountered in psychiatric practice.

Anxiety states and disorders amplify the symptoms and impairment associated with vestibular dysfunction. Five patients with inner ear vestibular dysfunction and anxiety were prospectively treated with fluoxetine, 20-60 mg/day, and received an extensive battery of assessments at baseline and after 12 weeks of treatment. Fluoxetine led to significant or near significant reductions in anxiety measures and in impairment due to dizziness; improvements in clinical balance function and vestibular function were less clear. The data add to the literature suggesting a role for selective serotonin reuptake inhibitors in the treatment of dizziness and anxiety.

Tai Chi (TC) is a comparatively new intervention for peripheral vestibular hypofunction, which is often treated with vestibular rehabilitation (VR). We compared gaze stability (GZS), whole-body stability (WBS) and footfall stability (FFS) during locomotion among 26 people with vestibulopathy (VSP), randomized into two treatment arms (13 TC and 13 VR). Each intervention program was offered for 10 weeks. GZS improved more for VR than for TC, but WBS (and FFS) improved more for TC than for VR. There was a significant relationship between changes in GZS and WBS for the VR subjects (r=0.60, p=0.01), but not for TC subjects. There was a significant relationship between changes in WBS and FFS for both VR (r=0.65, p0.01) and TC (r=0.58, p=0.02) groups; the relationship disappeared in the VR but not the TC group when controlling for GZS. These findings suggest that VR and TC both benefit patients with VSP but via differing mechanisms. Moreover, these data are the first to test the assumption that improving gaze control among patients with VSP perforce improves postural stability: it does not. We conclude that GZS is most improved in those who receive VR, but that TC improves WBS and FFS without improving GZS, suggesting patients with VSP can rely on non-gaze related mechanisms to improve postural control.

To evaluate the rationale and scientific support for Tai Chi as an intervention for vestibulopathy and to offer recommendations for future studies.A computer-aided search, including MEDLINE and Science Citation Index, to identify original Tai Chi studies published in English; relevant references cited in the retrieved articles were also included.A preliminary screening selected all randomized controlled trials (RCTs), non-RCTs, case-control studies, and case series that included Tai Chi as an intervention and had at least 1 outcome variable relevant to postural stability.Authors critically reviewed studies and summarized study designs and outcomes in a summary table.Twenty-four Tai Chi studies met screening criteria. No studies specifically studying Tai Chi for vestibulopathy were found. Collectively, the 24 studies provide sometimes contradictory but generally supportive evidence that Tai Chi may have beneficial effects for balance and postural impairments, especially those associated with aging. Ten RCTs were found, of which 8 provide support that Tai Chi practiced alone, or in combination with other therapies, can reduce risk of falls, and/or impact factors associated with postural control, including improved balance and dynamic stability, increased musculoskeletal strength and flexibility, improved performance of activities of daily living (ADLs), reduced fear of falling, and general improvement in psychologic well-being. Studies using other designs support the results observed in RCTs.At present, few data exist to support the contention that Tai Chi specifically targets the impairments, functional limitations, disability, and quality of life associated with peripheral vestibulopathy. There are, however, compelling reasons to further investigate Tai Chi for vestibulopathy, in part because Tai Chi appears useful for a variety of nonvestibulopathy etiologic balance disorders, and is safe. Especially needed are studies that integrate measures of balance relevant to ADLs with other psychologic and cognitive measures; these might help identify specific mechanisms whereby Tai Chi can remedy balance disorders.

The treatment of two patients with cerebellar dysfunction is described. One patient was a 36-year-old woman with a 7-month history of dizziness and unsteadiness following surgical resection of a recurrent pilocystic astrocytoma located in the cerebellar vermis. The other patient was a 48-year-old man with cerebrotendinous xanthomatosis (CTX) and diffuse cerebellar atrophy, and a 10-year history of progressive gait and balance difficulties. Each patient was treated with a 6-week course of physical therapy that emphasized the practice of activities that challenged stability. The patient with the cerebellar tumor resection also performed eye-head coordination exercises. Each patient had weekly therapy and performed selected balance retraining exercises on a daily basis at home. Measurements taken before and after treatment for each patient included self-perception of symptoms, clinical balance tests, and stability during selected standing and gait activities; for the patient with the cerebellar tumor resection, vestibular function tests and posturography were also performed. Both patients reported improvements in symptoms and demonstrated similar improvements on several kinematic indicators of stability during gait. The patient with the cerebellar tumor resection improved on posturography following treatment, whereas the patient with CTX improved on clinical balance tests. This case report describes two individualized treatment programs and documents functional improvements in two patients with different etiologies, durations, and clinical presentations of cerebellar dysfunction. The outcomes suggest that patients with cerebellar lesions, acute or chronic, may be able to learn to improve their postural stability.

Summary: Purpose: To describe a late complication of hemispherectomy in a patient in whom symptoms of hydrocephalus developed 36 years after her left-sided hemispherectomy, the longest delay on record. Methods: Hemispherectomy has been successfully used in the treatment of intractable epilepsy associated with infantile-type hemiplegia for a half century. Of the patients, however, up to 33% have late increased cerebrospinal fluid pressure complications attributed to superficial cerebral hemosiderosis. Through a retrospective case analysis, we describe such complications in a 52-year-old woman with cognitive impairment, gait instability, urinary incontinence, and right hemineglect 36 years after her initial procedure. Results: Quantitative, objective measures of cognition and gait-laboratory testing confirmed the patient's favorable clinical response to ventriculoperitoneal shunting, as well as the complete resolution of her symptoms, including the atypical occurrence of right-sided hemineglect. Conclusions: This case uniquely demonstrates the clinical features of a late complication of hemispherectomy while documenting the longest reported delay for developing such adverse sequelae. We also emphasize the need for more extensive follow-up studies to assess the extent of posthemispherectomy complications.

We describe the treatment of two patients with peripheral vestibular dysfunction using a novel, staged exercise program. Response to treatment was documented. The first patient, a 62-year-old woman with unilateral vestibular dysfunction (UVD) and a 6-month history of disequilibrium following herpes zoster oticus resulting in damage to the right inner ear, was treated with an 8-week course of vestibular physical therapy. During the 8 weeks, the patient attended weekly physical therapy sessions and was trained to perform vestibular adaptation exercises on a daily basis at home. The second patient, a 53-year-old woman with progressive disequilibrium secondary to profound bilateral vestibular hypofunction (BVH), was treated with a 16-week course of vestibular physical therapy. During the first 8 weeks, the patient attended weekly physical therapy sessions and was trained to perform vestibular adaptation and substitution exercises on a daily basis at home. During the second 8 weeks, the patient continued performing vestibular physical therapy exercises at home independently. Vestibular function (sinusoidal vertical axis rotation testing), postural control (clinical tests and posturography), stability during the performance of selected activities of daily living (ADLs), and self-perception of symptoms and handicap were measured prior to and at the conclusion of treatment for both patients and at the midpoint of treatment for the patient with BVH. After 8 weeks of treatment, both patients reported improvements in self-perception of symptoms and handicap and demonstrated objective improvements in clinical balance tests, posturography, and several kinematic indicators of stability during the performance of selected ADLs. Further improvements were noted in the patient with BVH after 16 weeks of treatment. Improvements in postural control were noted after 8 weeks of treatment for the patient with UVD and after 16 weeks for the patient with BVH. Vestibular function improved during the course of treatment for the patient with UVD only. These case reports describe two different individualized treatment programs and document self-reported and laboratory-measured functional improvements in two patients with vestibular deficients--one with unilateral damage and one with bilateral damage.

Vestibular rehabilitation (VR) is increasingly popular, but few data exist to support enthusiasts' claims of efficacy in improving functional abilities of patients with bilateral vestibular hypofunction (BVH). A double-blind, controlled study of eight subjects (mean, 64 +/- 12 years; seven females, one male) with bilateral vestibular hypofunction was conducted. Subjects in group A received 8 weeks of VR followed by 8 weeks of home VR exercises, whereas those in group B received 8 weeks of control treatment (isometric strengthening exercises) followed by 8 weeks of VR. At the end of 8 weeks, group A walked 8% faster and, during paced gait and stair-climbing, with greater stability, evidenced by a 10% larger maximum moment arm and a 17% decreased double-support duration during gait and stair stance. Group B improved less than 1% during the control treatment. Self-reported Dizziness Handicap Inventory scores did not differ significantly between control and active VR. All subjects improved compared with baseline tests at the 16-week post-test on both functional testing and on the Self-reported Dizziness Handicap Inventory scale. We conclude that in this small sample, VR effectively improved functional, dynamic stability during locomotion, but even strengthening exercises result in self-reported symptomatic improvement.

We studied the discharge pattern of single motor units (SMUs) in the left and right biceps muscles from a patient with nonspastic weakness of the left arm. Detailed statistical analysis of the behavior of discharge patterns of 4 of 4 single motor units on the affected side showed abnormalities with characteristic features of an upper motor neuron lesion. Five out of 5 single motor units recorded from the right biceps were normal. An upper motor neuron lesion affecting the left arm, predicted by our results, was confirmed by magnetic resonance imaging (MRI), which showed a lesion in the right precentral gyrus. It appears that changes in single motor unit firing characteristics, caused by an upper motor neuron lesion, can be detected at a time when there is no evidence of increased "tone" and/or hyperreflexia (spasticity) in the affected extremity.

The Naval Surface Warfare Center (NAVSWC) has actively supported the Warfare System Architecture and Engineering (WSA&E) Program since it began in FY 86. This report summarizes the WSA&E Program to date and NAVSWC's participation in the program for FY 90. NAVSWC led the force team in integrating the warfare mission area working group assessments into a total force context. As principal technical agent for electronic warfare and mine warfare, NAVSWC directed assessment efforts in these respective areas and participated in force integration team meetings. NAVSWC continued to provide major technical antiair warfare, antisubmarine warfare, and strike and antisurface warfare support.

Review of computed tomographic (CT) scans of 49 consecutive patients with surgically excised acoustic neuromas revealed positive scans in 80% following contrast enhancement, with 20% false negative scans. All tumors over 2 cm in diameter were shown by optimal scans with contrast enhancement. The positive scans were evaluated to determine the accuracy of the size of the lesions as predicted by the scan. A radiological approach to the evaluation of suspected acoustic neuromas is suggested.

An entity of episodic true vertigo of delayed onset following sudden and profound sensorineural hearing loss is described. Data on 12 patients and three case reports are presented. The latency between sudden deafness and the onset of the vertigo varied from 1 to 68 years. The vestibular symptoms are identical to the vestibular symptoms of Ménière's disease, and there is some evidence that endolymphatic hydrops in the previously deafened ear represents at least part of the labyrinthine pathology. Labyrinthectomy in the deaf ear was curative. Tentatively, this entity is best considered a variant of Ménière's disease.

Presentation of Case A 72-year-old man was admitted to the hospital for evaluation of "chronic meningitis." The patient was in a stable state of health until one year earlier, when he began to expe...

An ultrastructural analysis of the ampulla and ureter of the cricket, Acheta domesticus, is presented. The excretory system of the cricket is unusual in that the 112 Malpighian tubules do not attach directly to the gut, but fuse to form a bladder-like ampulla which is joined to the colon by a muscular ureter. The ampulla consists of two cell types, primary and regenerative. Primary cells secrete large numbers of membrane-bound vesicles into the lumen and also appear to be involved in fluid reabsorption. Regenerative cells are very small and form a layer just beneath the basal lamina of the ampulla. They are believed to differentiate and replace sloughed off primary cells. The ureter is a muscular tube lined with cuticle which connects the ampulla (endoderm) with the colon (ectoderm). The probable origin and significance of the morphological modifications of the excretory system are discussed.

Presentation of Case A 43-year-old right-handed man was admitted to the hospital because of headache and visual disturbances. He was well until three days earlier, when he experienced the sudden on...

Presentation of Case A 24-year-old man was admitted to the hospital because of collapse. He was well until 17 months earlier, when he received a shotgun blast in the face, without loss of consciousness. He was taken to the Emergency Ward, where examination showed a massive cavity that involved the nose, mouth, and chin. Fractures of the left mandible and both zygomas and a comminuted fracture of the nose and the right orbital floor were demonstrated on x-ray films (Fig. 1). The left orbital floor was absent, as were the anterior antral walls and the hard palate. A tracheostomy was . . .

• Two young male homosexuals developed prodromal syndrome followed by penicillin-responsive meningitis and the acute onset of pure motor hemiplegia. The clinical and laboratory features are consistent with meningovascular neurosyphilis. Basis pontis infarctions were subsequently demonstrated on magnetic resonance imaging scans. To our knowledge, this is the first description of syphilitic arteritis as a pathophysiologic basis for pure motor hemiplegia.

Large bilateral lesions in the mesencephalic reticular formation of rats led to severe aphagia and adipsia. Smaller bilateral mesencephalic lesions in the midreticular formation, between the red nucleus and aqueduct in the dorsoventral axis, were most effective in producing alterations in feeding behavior. Lesions restricted to the extreme lateral reticular formation, tectum, central gray matter or substantia nigra had little or no effect on food and water intake. Hyperphagia was observed in one rat with lesions caudal to the red nucleus at the edges of the central gray matter. The syndrome following small mesencephalic lesions was similar to the aphagicadipsic syndrome following lateral hypothalamic damage; most animals recovered within 1 or 2 weeks. Both direct current and radio-frequency current were effective in producing the syndrome. Neurological and behavioral symptoms, other than those related to food and water intake, were transitory.

A battery of tests with electronystagmography were performed on two groups of patients, one in which posterior fossa abnormalities had been confirmed independently by neurologic findings, contrast studies, or surgery; the other group consisted of what seemed clinically clear cut peripheral VIII nerve or labyrinthine disturbances. The two groups were compared statistically for the incidence of factors thought to indicate the presence of brain stem lesions. No single factor is absolutely reliable by itself as an indicator of brain stem disease, but the use of a test battery permits a much more accurate indication of probability of the presence of brain stem lesions.

An ultrastructural analysis of the Malpighian tubules of the cricket, Acheta domesticus, is presented. The excretory system of the cricket is unusual in that the 112 Malpighian tubules do not attach directly to the gut, but fuse to form a bladder-like ampulla which is joined to the colon by a muscular ureter. The tubules have three structurally distinct segments and consist of four cell types. Attached by basal lamina to the outer surface of the distal tip are nodules, consisting of small cells on membranous stalks. These are presumed to serve as attachments to the body wall. The distal 20% of the tubule is hyaline, consisting of a monolayer of squamous cells that appear to be secretory. The mid-tubule comprises 75% of the total length and is the primary region for fluid secretion. It is also characterized by having large numbers of laminate spheres in the cytoplasm of the cells. The proximal 5% of each tubule consists of more columnar cells and may function in fluid resorption. The relationship between structural features and known physiological functions are discussed.

Although old or recent infarcts of a cerebellar hemisphere in the territories of the posterior inferior (PICA), superior, or anterior inferior cerebellar arteries are commonplace autopsy findings, in no case have corresponding clinical symptoms been clearly identified. We have studied three cases, two clinicopathologically and one clinicosurgically, in which an acute infarct involving only the cerebellum lay in the PICA territory distal to the branches to the medulla oblongata. The clinical manifestations consisted of rotatory dizziness intensified by motion, nausea, vomiting, imbalance, and nystagmus. In two cases, the clinical diagnosis had been a benign labyrinthine disorder. Recognition of a syndrome corresponding to cerebellar infarction in the PICA territory is important insofar as it assists in the differential diagnosis of dizziness. It becomes of crucial importance when cerebellar infarction is the prelude to cerebellar swelling and brain stem compression leading to coma and death unless surgically relieved.

Patients undergoing hemodialysis and renal transplan­ tation for the treatment of end-stage renal disease are subject to considerable psychological and metabolic stress. Psychotic episodes infrequently occur in this patient population. I .' In the following cases three se­ verely ill patients demonstrated psychotic behavior and abnormal electroencephalographic (EEG) findings consistent with a diagnosis of complex partial seizure. They improved significantly in mental status after anti­ convulsant treatment was initiated.

Seventy percent of 80 surgically proven acoustic neuromas were visualized on preoperative computed tomography (CT) scans. Many more tumors were seen on contrast enhanced scans than on unenhanced scans (55 vs 25). No intracanalicular tumors and only one of 15 tumors less than 2 cm in size were visualized on CT scan. Most medium size tumors (2.0–3.0 cm) and all large tumors (>3.0 cm) were visualized on CT scan when optimal technique was used. Positive CT scans often replace more invasive diagnostic studies in the investigation of acoustic neuromas. Negative scans do not rule out tumors as intracanalicular, and small tumors are usually not visualized with current techniques. If there is clinical suspicion of an acoustic neuroma, positive contrast posterior fossa cisternography should be done when the CT scan is negative.

Cerebellopontine angle (CPA) meningiomas constitute about 1% of intracranial meningiomas. The clinical aspects of a series of 32 patients with surgically confirmed CPA meningiomas are analyzed. The most common symptoms at the time of the initial evaluation were from the eighth cranial nerve (unilateral hearing loss — 24 patients, vertigo or imbalance — 19 patients, tinnitus — 11 patients), and the fifth cranial nerve (altered sensation — 9 patients, facial pain — 5 patients). On examination, the most common findings were absent caloric response (19 patients), nystagmus (16 patients), diminished facial sensation (14 patients), ataxia (13 patients), reduced hearing (9 patients), and facial weakness (9 patients). There was often a long interval from the onset of symptoms to the correct diagnosis of a tumor. Brain stem auditory evoked potentials, blink reflex testing, posterior fossa myelography, computerized tomographic scanning, and angiography were abnormal in all patients in whom the test was done, but all tests were not performed on all patients. Computerized tomographic scanning and angiography are important for definitive diagnosis and for planning surgical treatment. The histopathology of the temporal bone was studied in three patients with meningiomas in the region of the internal auditory meatus.

The pathogenesis of Pelizaeus-Merzbacher (P-M) disease is unknown. A 17-year-old male, whose brother died at 12 years with pathological findings of classical P-M disease, had congenital nystagmus, ataxia, dementia, and progressive quadriparesis. Electronystagmographic testing showed prolonged latency and slow phase duration during rotation and caloric stimulation. These findings suggest ongoing involvement of myelinated fibers in brain stem-cerebellar connections which may underlie the abnormal eye movements of P-M disease. Electron microscopic examination of CSF ultrasediment (100,000 g) disclosed scattered cells containing lipid droplets (1-3 μ diameter) with unique satellite aggregation which were not represented in over 200 normal and pathological controls. In the white matter of the deceased sibling, the activities of cholesterol ester esterase (pH 6.6) and 2′3′-cyclic nucleotide phosphohydrolase were decreased to 40% and 20% of controls, respectively. The cholesterol ester fraction was 10X normal, and this fraction contained disproportionately increased amounts of oleic as opposed to arachidonic and other polyunsaturated fatty acids. This pattern is highly similar to that in other demyelinating diseases. These clinical and biochemical findings suggest that P-M disease is characterized by a chronic ongoing demyelinating process. (Supported in part by USPHS grants HD 05515 and HD 04147)