Carpal tunnel syndrome and the Riche-Cannieu anastomosis: electrophysiologic findings.

Two cases of carpal tunnel syndrome with Riche-Cannieu anomalies are reported. Despite complete absence of a median nerve evoked compound muscle action potential from the thenar eminence, these patients had significant preservation of function and minimal muscle atrophy. Activation of the ulnar nerve at both the wrist and elbow generated easily obtainable compound muscle action potentials from the thenar eminence with initial negative onset. This observed preservation of function and electrophysiologic responses are best explained by the presence of a Riche-Cannieu anastomosis innervating the thenar eminence through branches from ulnar nerve. To our knowledge there has not been a report of similar cases in patients with profound carpal tunnel syndrome and a Riche-Cannieu anomaly. We review the clinical findings, the electrodiagnostic data, and the impact of a Riche-Cannieu anastomosis on advanced carpal tunnel syndrome.

Neurocysticercosis: focus on intraventricular disease.

Intraventricular neurocysticercosis is of concern because it is associated with a poorer prognosis than is parenchymatous disease. Frequently, associated hydrocephalus occurs, which may recur after treatment. We report on 11 patients with intraventricular cysticercosis (from a larger case series of 33 patients) and evaluate clinical presentations, neuroimaging findings, and responses to treatment, especially of ventricular disease. Intraventricular cysticercosis represented 33% of our cases. Seven patients presented with increased intracranial pressure; four required ventriculoperitoneal shunting. Parenchymatous symptomatic cysticercosis is largely a result of the host inflammatory response, presenting in our series with epileptic seizures in 73% of the patients (tonic clonic generalized seizures occurred in 64% and partial simple seizures in 9%). The prognosis for parenchymatous inflammatory disease is good. We advocate the use of anthelmintic treatment with albendazole in all cases of intraventricular cysts, and if hydrocephalus occurs, then shunt procedures or ventriculostomy is necessary. These patients must be monitored closely for recurrent hydrocephalus.

Association of intravenous phenytoin toxicity with demographic, clinical, and dosing parameters.

Previous studies investigating intravenous phenytoin toxicity have been largely anecdotal, and have inferred an association with older patients, cardiovascular disease, and higher doses, concentrations, and infusion rates of phenytoin. This investigation sought to elucidate both the incidence and nature of acute intravenous phenytoin toxicity in emergency department patients, and to identify any demographic, clinical, or dosing associations with toxicity, by analyzing a retrospective case series over 3 years in a municipal teaching hospital. A consecutive series of 164 patients who received intravenous phenytoin loading in the emergency department following acute seizure presentation was identified. Demographic, clinical, and dosing data were collected, and the nature of toxicity was noted. Data were then analyzed statistically for potential associations with toxicity. Eight cases of hypotension and no apnea or arrhythmias were noted in the 164 patients (4.9% incidence). Analysis of demographic, clinical, and dosing data found statistically significant associations between hypotension and both a lower phenytoin dose administered (537 mg in hypotensive patients v 787 mg in normotensive patients, P = .00046) and the presence of abnormal neurological signs at initial presentation (20% incidence when abnormal signs present v 3.5% incidence when absent, P = .026). No other associations were found between toxicity and other variables. This sample size could detect differences ranging from 4% to 11% in complication rate (hypotension) for the various demographic, clinical, and dosing parameters with a statistical power of 80%. It was concluded that the incidence of hypotension from intravenous phenytoin administration in this study population was approximately 5%, and the incidence of apnea and cardiac arrhythmia in this series was 0%. No associations with age, comorbidities, or infusion rates were found, in contrast to other studies. Association of intravenous phenytoin toxicity with lower phenytoin dose is likely related to prompt cessation of the drug once signs of toxicity occur. The possible association of toxicity with abnormal initial neurological signs has not previously been reported and may possibly define a population at risk if validated by prospective research in additional populations.

Cerebral arterial thrombosis as a complication of paroxysmal nocturnal hemoglobinuria.

Venous thrombosis is a frequent complication in patients with paroxysmal nocturnal hemoglobinuria (PNH). However, arterial thrombosis is rare, and cerebral arterial thrombosis has been reported only in postmortem studies. We discuss the case of a PNH patient in whom both clinical and neuroimaging findings were compatible with cerebral arterial and venous thrombosis.

Residual subclinical impairment in patients who totally recovered from Guillain-Barré syndrome: impact on military performance.

Patients who have clinically recovered from Guillain-Barré syndrome (GBS) may exhibit a deficit during strenuous exercises that require maximal effort and muscular endurance. The Army Physical Fitness Test (APFT) is a quantitative tool that challenges neuromuscular endurance and unmasks a subclinical deficit in soldiers who have apparently recovered from GBS. The impact of this subclinical deficit on active duty soldiers and strategies for managing their poor performance on the APFT are discussed.

The thoracic outlet syndrome: controversies, overdiagnosis, overtreatment, and recommendations for management.

This review is an objective critique of the thoracic outlet syndrome, with emphasis on the need to separate true neurogenic and vascular syndromes from nonspecific ones. Major controversies in the diagnosis and management of thoracic outlet syndromes are discussed, with an analysis of major pitfalls encountered in the diagnosis and treatment of patients with nonspecific syndromes. Recommendations to improve diagnostic methods in patients with chronic neurovascular abnormalities in the upper extremities are outlined.

Intrathecally administered natural human fibroblast interferon reduces exacerbations of multiple sclerosis. Results of a multicenter, double-blind study.

A randomized, double-blinded, placebo-controlled, two-year multicenter study demonstrated that natural human fibroblast interferon (interferon beta) administered intrathecally (IT) is effective in reducing the exacerbations of exacerbating-remitting multiple sclerosis (MS). The mean reduction in exacerbation rate of 34 patients with MS who received interferon beta administered IT was significantly greater during the study than that of 35 control patients who received placebo. The prestudy exacerbation rates were comparable for both patients who received interferon beta and control patients, but the exacerbation rate of patients receiving interferon beta at the end of the study was significantly lower than that of the control patients. Interferon beta was administered by nine or ten lumbar punctures for the first six months of the study, and observations were continued for two years. In 95% of the recipients, interferon beta therapy was well tolerated, and the side effects experienced were clearly acceptable for the benefits achieved. Low doses of indomethacin dramatically reduced the toxicity of interferon beta therapy and played an important role in successful double blinding. This study confirms a preliminary report on 20 patients that initially suggested that interferon beta administered IT was of benefit in patients with MS. The number of treatments was fewer and the dosage of interferon beta administered was less in the present study than in the preliminary one. It is possible that even fewer treatments with lower doses of interferon beta administered might provide a similar degree of prophylaxis against exacerbations.

Multicentre double-blind study of effect of intrathecally administered natural human fibroblast interferon on exacerbations of multiple sclerosis.

In this randomised, double-blind, placebo-controlled, 2-year multicentre study intrathecally administered natural human fibroblast interferon (IFN-B) was effective in reducing exacerbations of multiple sclerosis (MS) in patients with exacerbating/remitting disease. The mean reduction in exacerbation rate of 34 patients who received IFN-B (recipients) was significantly greater during the study than that of 35 patients who received placebo (p less than 0.04). The prestudy exacerbation rates were comparable in recipients and controls, but the rate at the end of the study was significantly lower in recipients than in controls (p less than 0.001). IFN-B was given by nine or ten lumbar punctures over the first 6 months of the study, and patient observations continued for 2 years. IFN-B was well tolerated in 95% of the recipients, and the side-effects experienced were clearly acceptable for the benefits achieved. Low doses of indomethacin reduced the toxicity of IFN-B and played an important role in successful double-blinding.

Peripheral dystonia.

We studied four patients with distal, action-induced involuntary postures of the hand that could be considered focal dystonia. All four patients had electrophysiologic findings consistent with peripheral nervous system lesions (pronator teres syndrome, radial nerve palsy, lower brachial plexus lesion, or median nerve lesion). With varying success, patients were treated with carbamazepine, trihexyphenidyl, methocarbamol, and wrist splinting. We wish to emphasize that peripheral entrapment and brachial plexopathy should be added to the causes of secondary dystonias.

Spinal syphilis: the problem of fluorescent treponemal antibody in the cerebrospinal fluid.

Spinal manifestations of syphilis are now uncommon. Three adults with presumptive nontabetic spinal syphilis are presented. This paper should serve as a reminder to physicians that cases of late syphilis continue to occur and may be manifested as obscure spinal syndromes and be misdiagnosed unless the possibility of syphilis is constantly kept in mind. Some of the clinical dilemmas associated with the reactivity of fluorescent treponemal antibody in the cerebrospinal fluid are discussed,