Blink reflexes and the silent period in tetanus.

Abnormalities of the silent period (SP) and blink reflexes occur in diseases that interfere with inhibitory pathways, such as tetanus and stiff-person syndrome (SPS). The SP is abnormal in tetanus but not in SPS. Studies of the blink reflex in tetanus are limited. In this report, a patient with generalized tetanus is described. The masseteric-and mixed-nerve SP was absent or truncated. In contrast to SPS, blink reflex studies revealed no bilateral R1 component, and a discrete R3 was only present ipsilateral to right supraorbital stimulation. This reflects the distinct inhibitory pathways underlying these disorders.

Spontaneous intracranial hypotension resulting in stupor caused by diencephalic compression.

A 51-year-old man had a 4-month history of progressive headache and gradual onset of somnolence. MRI suggested spontaneous intracranial hypotension (SIH) with diencephalic compression, but he did not improve after three epidural blood patches. He became alert following intrathecal saline infusion that normalized his CSF pressure. A CSF leak was noted on spinal MRI and confirmed with CT contrast myelography. Surgical ligation of a torn dural root sleeve isolating a ruptured Tarlov's cyst resulted in permanent cure.

An algorithm for the evaluation of peripheral neuropathy.

The diagnosis of peripheral neuropathies can be frustrating, time consuming and costly. Careful clinical and electrodiagnostic assessment, with attention to the pattern of involvement and the types of nerve fibers most affected, narrows the differential diagnosis and helps to focus the laboratory evaluation. An algorithmic approach to the evaluation and differential diagnosis of a patient with peripheral neuropathy is presented, based on important elements of the clinical history and physical examination, the use of electromyography and nerve conduction studies, autonomic testing, cerebrospinal fluid analysis and nerve biopsy findings. The underlying cause of axonal neuropathies can frequently be treated; demyelinating neuropathies are generally managed with the assistance of a neurologist.

Myokymic discharges of the tongue after radiation to the head and neck.

We report two patients who developed myokymic discharges of the tongue after radiation therapy. One patient had carcinoma of the nasopharynx, and the other had a chemodectoma of the middle ear. Radiation therapy may damage the hypoglossal nerve and cause myokymia of the tongue, similar to myokymic discharges associated with brachial plexopathies after radiation therapy.