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We report a case of a small cortical infarction in the postcentral gyrus that presented an isolated hemicape-like sensory disturbance. A 47-year-old man suddenly developed numbness and paresthesia in the left neck, shoulder, arm, and upper trunk. Examination revealed hypoesthesia to touch and pain in these areas along with a hemicape-like distribution. The sensitivity to cold and vibration was normal, and two-point discrimination and graphesthesia were preserved. The patient had a normal visual field, muscle strength, and reflexes, and there were no neuropsychological deficits. Magnetic resonance imaging (MRI) demonstrated a fresh, small cerebral infarction in the right postcentral gyrus, which was superior medial to the precentral knob. The area of infarction in this patient corresponds well with the area of the upper trunk, neck, head, shoulder, and arm in the sensory homunculus drawn by Penfield and Rassumussen. The spinal MRI was normal. Transesophageal echocardiography disclosed a patent foramen ovale with a right-to-left-shunt. The patient was diagnosed as having acute cerebral infarction, probably due to paradoxical embolism, and was treated with warfarin. A small localized infarct in the postcentral gyrus can present an isolated sensory disturbance with an atypical hemicape-like distribution.

Shoulder pain is a common symptom, resulting not only from bone and shoulder joint diseases, but also from neurogenic lesions. Entrapment neuropathy of the suprascapular nerve also causes shoulder symptoms. Conduction of the suprascapular nerve was studied in 12 healthy control subjects and 25 patients suffering from shoulder pain and/or dysfunction. Surface stimulation was performed at Erb's point, and compound muscle action potentials(M waves) were recorded from the supraspinatus and the infraspinatus muscles with concentric needle electrodes. To determine the optimal site for recording M waves from the infraspinatus muscle, simultaneous multi-channel recordings of M waves using pairs of surface electrodes were obtained from different sites over the infraspinatus muscle. In two patients, latency of the M waves to the infraspinatus muscle was prolonged, whereas that to the supraspinatus muscle was normal. These findings indicate entrapment neuropathy at the spinoglenoid notch. In three patients, the latency to the infraspinatus and supraspinatus muscles was prolonged. These findings are compatible with entrapment neuropathy at the suprascapular notch. The latency to the supraspinatus and infraspinatus muscles was prolonged in patients with brachial plexus injury and in those with suprascapular nerve injury. In patients with myopathy, those with neuralgic amyotrophy and those with cervical radiculopathy, the latency was normal. Thus, conduction studies of the suprascapular nerve using multiple-channel recordings are useful, especially for the diagnosis of entrapment neuropathy of the suprascapular nerve.

A case of the superior posterior serratus muscle on the left side supplied by both the intercostal and dorsal scapular nerves was observed in a 67-year-old Japanese male cadaver at Sapporo Medical College, 1991. The innervation and intramuscular nerve distribution of this case was investigated using a binocular microscope. The belly of this muscle consisted of three parts, which were inserted into the second, third and fourth ribs, respectively (Fig. 1). The second part inserted into the third rib consisted of two offshoots, namely a medial and a lateral offshoot. The latter almost totally covered the first part inserted into the second rib. This muscle was innervated by twigs from the dorsal scapular nerve (C5) and the superficial intercostal nerves (Th1 & Th2) of Kodama (Kodama, 1986). The superficial intercostal nerve of the first thoracic segment gave off two twigs to the muscle, the superior (medial) and inferior (lateral) (Fig. 1). The intramuscular nerve distribution of this case demonstrated that, except for the lateral offshoot, the innervation of the muscle belly showed roughly segmental tendency though all of the twigs communicated with each other (Fig. 2). The lateral offshoot was chiefly innervated by the twig from the dorsal scapular nerve. It is apparent that the muscle primordium with the twig from C5, which ordinarily is situated at the cranialmost portion of the belly, instead came to rest between the first part and the medial offshoot of the second part. As a result, this muscle belly was innervated partially in a non-segmental manner.(ABSTRACT TRUNCATED AT 250 WORDS)