Search

A 55-year-old man presented a slowly progressive sensory disorder, predominantly in both lower limbs, and gait disturbance. Neurological examinations revealed abnormal sensation and spasticity in both lower limbs, and a wide-based gait. Although examination revealed mild hyperchloremia and decreased motor conduction velocity in the peroneal nerve, head and whole spine MRI, and spinal fluid examination were normal. His job history revealed he had been engaged in metal cleaning work using 1-bromopropane (1-BP) for three years. His serum bromide concentration was increased to 175.6 mg/l (standard value: 5 or less), so we diagnosed him as having 1-BP neurotoxicity. The serum bromide concentration decreased after avoidance of exposure to 1-BP, but the gait disturbance remained. It was considered that we should obtain a detailed job history and measure the serum bromide concentration in patients with a sensory disorder in the extremities and gait disturbance of unknown origin.

We performed hyperbaric oxygen (HBO) therapy for 3 patients with delayed neuropsychiatric encephalopathy induced by carbon monoxide (CO) poisoning. All patients were male and around 50 years old, and they had not received HBO therapy within 24 h after CO poisoning, even though they showed severe consciousness disturbance. In these patients, delayed neuropsychiatric encephalopathy appeared about 25 days after acute CO poisoning, and HBO therapy was initiated within 8 days after disease onset. Although the condition of 2 of the patients worsened initially, they showed significant improvement of neurocognitive impairment after 30 sessions of HBO therapy. The clinical courses of these patients suggest that the effect of HBO therapy can be evaluated after 30 sessions. To evaluate the validity of the indices of the clinical effect of HBO therapy, we performed brain magnetic resonance imaging, single photon emission computed tomography, electroencephalography (EEG), and neurocognitive tests (HDS-R, and Wechsler Adult Intelligence Scale-Revised or III). Our results showed that changes in EEG signals and neurocognitive tests were closely correlated with the patients' clinical courses.

A 67-year-old man living alone was admitted for acute disturbance of consciousness during winter. He presented with semicoma, a decorticate posture, and exaggerated tendon reflexes of the limbs, but brainstem reflexes were intact. The carboxyhemoglobin (COHb) level was normal in arterial blood gas on admission, and protein in cerebrospinal fluid was increased without pleocytosis. Brain MRI showed diffuse T2 high intensities in the deep white matter bilaterally without a contrast effect and abnormal T1 intensity in the pallidum. (1)H-MR spectroscopy (MRS) of the white matter lesion demonstrated findings suggesting demyelination as an increased choline peak, enhanced anaerobic metabolism as increased lactate and lipids peaks, and reduced neurons as a decreased N-acetylaspartate peak, which corresponded to delayed encephalopathy due to the interval form of carbon monoxide (CO) poisoning. The possibility of CO exposure due to coal briquette use 2 weeks before the symptomatic onset was indicated by his family, so he was diagnosed with CO poisoning. His consciousness slightly improved with corticosteroid therapy and repetitive hyperbaric oxygen therapy, but brain MRI and MRS findings did not improve. Characteristic MRS findings of leukoencephalopathy are helpful for diagnosing the interval form of CO poisoning in the case of a normal COHb level.

We report a case of encephalopathy seemingly caused by tacrolimus (FK506) in spite of blood concentration near the upper limit of therapeutic range. A 26-year-old man received FK506 to prevent acute graft-versus-host disease after hematopoietic stem cell transplantation. He underwent an intravenous injection of FK506 the day before transplantation (day -1). He developed headache, hypertension, nausea and vomiting from day 2 to day 3. A computed tomography scan showed a low density area with unclear border in the bilateral cerebellar hemispheres. Thereafter, these symptoms improved with discontinuation of FK506, which was strongly suggestive of encephalopathy caused by FK506. The blood concentration of FK506 at the onset of encephalopathy was 21.7 ng/mL. Although this value was slightly higher than the standard therapeutic range (10-20 ng/mL), it was within clinically acceptable range in the early stage after stem cell transplantation. This indicates that even if the blood concentration of FK506 is within the therapeutic range, encephalopathy may develop. In summary, although the blood concentration of FK506 is useful as an indicator for prevention of encephalopathy, we propose careful monitoring not only of the blood concentration but also clinical status for the detection of initial symptoms and prevention of aggravation.

Objectives: Some patients with acute carbon monoxide (CO) intoxication relapse into severe neuropsychiatric symptomes several weeks after the lucid interval. This serious neurological sequelae, delayed encephalopathy, is difficult to anticipate. Although magnetic resonance imaging (MRI) was reported to show characteristic findings, there has been few information on MRI during the lucid interval. We retrospectively reviewed MR images obtained within 15 days after the exposure, and analyzed whether MRI could predict delayed encephalopathy., Design: Retrospective, single-center study., Patients: Sixteen serial patients with severe CO intoxication, who were found unconscious and underwent hyperbaric oxygen therapy, and in whom MR-imagings were performed at least once within 15 days after the exposure., Measurements and Main Results: Although all 16 patients recovered consciouness, six of them (37.5 %) went into delayed encephalopathy (DE group) while the others did not (non-DE group). FLAIR images of all patients in DE group showed bilateral diffuse high intensity in white matter of centrum semiovale after the relapse of neuropsychiatric symptomes. In 4 of them, the identical findings were recognized earlier during the lucid interval. In contrast, no MR images of patients in non-DE group showed white matter hyperintensity (4/6 vs 0/10, p < 0.01). T2-hyperintensities in basal ganglia were seen not only in DE group (3 of 6 patients) but also in non-DE group (2 of 10). Diffusion-weighted images (DWI) were obtained in 10 patients (5 in each group). Although white matter hyperintensities in DWI were positive in 4 patients in DE group (none in non-DE group), 3 of them showed negative findings during the lucid interval., Conclusions: Bilateral symmetric white matter hyperintensity in MRI (T2WI/FLAIR) could be a good predictor of delayed encephalopathy after acute CO intoxication.

We examined the usefulness of Magnetic Resonance Imaging (MRI) test in the acute phase of carbon monoxide intoxication for forecasting delayed encephalopathy (DE). [Case 1] 26-year-old female. COHb 12%. Takotsubo (Ampulla) cardiomyopathy was supervened. Pallidal disorder was recognized in MRI test in the early stage. Although Prophylactic HBO was performed, DE began. 36 days later, disorder was recognized in large area, such as, in cerebral white matter and callosum, and abnormality was found in WMS-R and MMSE. Since HBO was performed, DE subsided. In MRI test, on the other hand, high signal range in cerebral white matter and callosum were gradually decreased and WMS-R and MMSE were improved. [Case 2] 19-year-old female. COHb 9.4%. The state was considered to be mild but pallidal disorder was found in MRI test at the beginning. DE did not start, then the part of pallidal disorder was narrowed. WMS-R and MMSE showed slightly low level. [Case 3] 19-year-old female. COHb 7.3%. The state was considered to be mild and there was no abnormal findings in MRI test in the early stage. DE did not start. [Case 4] 48-year-old male. COHb 48.9%. Rhabdomylosis was supervened, then ischemic change in a left radiate crown was recognized in the early MRI test. Since the third day, disorientation and restlessness had been developed, so that the patient was transferred to psychiatric department, though it was still difficult to distinguish the case from DE. Although the case is relatively mild, pallidal disorder is recognized in the early MRI test. Pallidal disorder alone can cause memory disorder and cognitive impairment. Even if pallidal disorder alone is recognized in the early MRI test, white matter disorder is developed with time, and then DE begins. If there are no typical carbon monoxide intoxication findings, some cases can be suspected as DE. It is useful to perform serial MRI test in order to prepare for delayed encephalopathy in carbon monoxide intoxication.

Methotrexate (MTX) is a major cause of treatment-related acute neurotoxicity. We report on clinical and imaging findings of reversibly restricted diffusion in a patient with transient encephalopathy after high dose MTX therapy for osteosarcoma. During the chemotherapy, a 19-year-old man was introduced for the evaluation of consciousness disturbance. Neurological examination revealed confusion, inability of speak at the onset On next day, there were still difficulties in swallowing and phonation, and furthermore deep tendon reflexes were hyperactive in bilateral lower limbs with positive Babinski responses bilaterally. By the 6th day, findings at neurological examination were completely normal. Initial imaging on presentation was performed using MRI. Diffusion weighted MRI clearly indicated areas of restricted diffusion within both centrum semiovale. These abnormalities were confirmed by the diffusion tensor (DT) technique (ADC and FA map). The follow-up MRI examinations using same protocol showed resolution of the ADC and FA abnormalities but increasing T2-signal changes. Neither contrast enhancement nor atrophy was encountered. Early detection of MTX white matter injury by DT image has the potential to alert the oncologist and neurologist to this event and provide a technique by which treatment of neurotoxicity can be monitored.

An 18-year-old female with myelodysplastic syndrome underwent an allogeneic cord blood transplantation in May 2005. The conditioning regimen consisted of total body irradiation, cytarabine and cyclophosphamide. The day of the cord stem cell transfusion was counted as Day 0. For acute GVHD prophylaxis, cyclosporine A (CsA) and methotrexate were used. Engraftment was achieved on Day 30, acute GVHD grade II developed on Day 45 and treatment with methylprednisolone for acute GVHD was started. On Day 68 the patient had generalized seizures accompanied by loss of consciousness, hypertension and left hemiparesis, and was intubated. A cranial CT scan showed a mass effect on the right basal ganglia, and high signal intensities on the T2-weighted and FLAIR images of a MR examination were detected in the bilateral basal ganglia and posterior lobes, the findings of which were compatible with a brain tumor or infectious disease. Since an increased level of apparent diffusion coefficient (ADC) values on the bilateral basal ganglia was noted, we suspected that vasogenic edema had caused the mass effect. She went into remission immediately after CsA treatment was discontinued. Therefore, this case was diagnosed as atypical reversible posterior leukoencephalopathy syndrome (RPLS) associated with CsA. CsA-induced encephalopathy presenting a mass effect in clinical imaging findings is very rare, and an ADC map may be useful for the diagnosis of RPLS.

We report a 54-year-old man (case 1) and a 79-year-old woman (case 2) who presented with encephalopathy of unknown cause. Both patients were on hemodyalysis and took an autumn mashroom, "sugihiratake" (Pleurocybella porrigens), two to three weeks prior to the onset of neurological alterations. The clinical syndrome of those patients was characterized by weakness and involuntary movements of the extremities (cases 1 and 2) or dysarthria (case 1) at the onset of the disease and subsequent intractable focal motor seizures, resulting in generalized status epilepticus or comatose state, six (case 1) or three (case 2) days after the disease onset. Epileptic seizures were gradually improved in both cases. On brain MRI of case 1, no relevant lesions were detectable at the onset day, but, 6 days after onset, T2-high intensity lesions were noted in the subcortical white matter of the insular cortex, claustrum, external capsule, putamen and globus pallidus on both sides. On brain CT scan of case 2, there were no apparent lesions at the onset day, but, 4 days after onset, low density areas were noted bilaterally in the subcortical white matter of the insular cortex. Electroencephalography of the two patients taken on a day of comatose state showed periodic synchronous discharge (PSD), which disappeared when their consciousness levels were improved. As far as we have examined, there was no findings to suggest the cause of the encephalopathy in routine laboratory examinations and various viral antibody studies of the blood and cerebrospinal fluid. The reported patients could constitute a newly recognized disease entity, "sugihiratake" encephalopathy. Our observations suggest that it can be an encephalopathy with subacute progression and affect mainly the basal ganglia. Neuroimaging study and electroencephalographic findings may help the diagnosis, although they may remain unremarkable for several days after onset of the neurological alterations.

We describe a 56-year-old woman with hyperammonemic encephalopathy caused by side effect of valproic acid (VPA). Ten months before the admission to our hospital, she had the first attack of convulsive seizure. Diagnosis of epilepsy was made, and the oral administration of VPA (800mg/day) was started at another hospital. Seizure was well controlled by VPA, until the recurrence of attack forced her to visit our hospital. Convulsive seizure disappeared immediately after intravenous administration of diazepam, but consciousness disturbance was prolonged for a few days. Since laboratory examinations revealed hyperammonemia without liver dysfunction, VPA was discontinued. Subsequently, her consciousness completely recovered. Other laboratory findings, including positive antinuclear antibody, antibodies to Sjögren's syndrome A, reduced lacrimal secretion in Schirmer's test, and cell infiltration in the salivary gland on lip biopsy specimen, suggested the presence of Sjögren's syndrome. The hyperammonemia occurs by the side effect of VPA, often has basal disease or drug interactions. It was, however, especially in patients with basal disease or other drugs, obscure whether (and how) Sjögren's syndrome contributed to the development of hyperammonemic encephalopathy in this case, since she took only VPA.