Human Rabies with Initial Manifestations that Mimic Acute Brachial Neuritis and Guillain-Barré Syndrome.

INTRODUCTION: Human rabies can be overlooked in places where this disease is now rare. Its diagnosis is further confused by a negative history of exposure (cryptogenic rabies), by a Guillain-Barré syndrome (GBS) type of presentation, or by symptoms indicating another diagnosis, eg, acute brachial neuritis (ABN). CASE PRESENTATION: A 19-year-old Mexican, with no past health problems, presented with a two-day history of left shoulder, arm, and chest pain. He arrived in Louisiana from Mexico five days prior to admission. Of particular importance is the absence of a history of rabies exposure and immunization. On admission, the patient had quadriparesis, areflexia, and elevated protein in the cerebrospinal fluid, prompting a diagnosis of GBS. However, emerging neurological deficits pointed towards acute encephalitis. Rabies was suspected on hospital day 11 after common causes of encephalitis (eg, arboviruses) have been excluded. The patient tested positive for rabies IgM and IgG. He died 17 days after admission. Negri bodies were detected in the patient's brain and rabies virus antigen typing identified the vampire bat as the source of infection. CONCLUSION: Rabies should be suspected in every patient with a rapidly evolving GBS-like illness-even if there is no history of exposure and no evidence of encephalitis on presentation. The patient's ABN-like symptoms may be equivalent to the pain experienced by rabies victims near the inoculation site.

Idiopathic brachial neuritis.

Parsonage-Turner syndrome (PTS) is a rare syndrome of unknown cause, affecting mainly the lower motor neurons of the brachial plexus. The brachial plexus is a group of nerves that conduct signals from the spine to the shoulder, arm, and hand. PTS is usually characterized by the sudden onset of severe 1-sided shoulder pain, followed by paralysis of the shoulder and lack of muscle control in the arm, wrist, or hand several days later. PTS can vary greatly in presentation and nerve involvement. Also known as brachial plexus neuritis or neuralgic amyotrophy, PTS is a common condition characterized by inflammation of a network of nerves that control and supply, or innervate, the muscles of the chest, shoulders, and arms. Individuals with the condition first experience severe pain across the shoulder and upper arm. Within a few hours or days, weakness, wasting (atrophy), and paralysis may affect the muscles of the shoulder. Although individuals with the condition may experience paralysis of the affected areas for months or, in some cases, years, recovery is usually eventually complete.

Distal symmetrical polyneuropathy: a definition for clinical research. A report of the American Academy of Neurology, the American Association of Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation.

The objective of this report was to develop a case definition of "distal symmetrical polyneuropathy" to standardize and facilitate clinical research and epidemiologic studies. A formalized consensus process was employed to reach agreement after a systematic review and classification of evidence from the literature. The literature indicates that symptoms alone have relatively poor diagnostic accuracy in predicting the presence of polyneuropathy; signs are better predictors of polyneuropathy than symptoms; and single abnormalities on examination are less sensitive than multiple abnormalities in predicting the presence of polyneuropathy. The combination of neuropathic symptoms, signs, and electrodiagnostic findings provides the most accurate diagnosis of distal symmetrical polyneuropathy. A set of case definitions was rank ordered by likelihood of disease. The highest likelihood of polyneuropathy (useful for clinical trials) occurs with a combination of multiple symptoms, multiple signs, and abnormal electrodiagnostic studies. A modest likelihood of polyneuropathy (useful for field or epidemiologic studies) occurs with a combination of multiple symptoms and multiple signs when the results of electrodiagnostic studies are not available. A lower likelihood of polyneuropathy occurs when electrodiagnostic studies and signs are discordant. For research purposes, the best approach to defining distal symmetrical polyneuropathy is a set of case definitions rank ordered by estimated likelihood of disease. The inclusion of this formalized case definition in clinical and epidemiologic research studies will ensure greater consistency of case selection.

Electrophysiologic Features of Inherited Demyelinating Neuropathies: A Reappraisal.

The observation that inherited demyelinating neuropathies tend to have uniform conduction slowing and acquired disorders (CIDP and variants) have nonuniform or multifocal slowing was made before the identification of genetic defects of specific myelin constituents that cause the different forms of Charcot-Marie-Tooth and other inherited disorders involving peripheral nerve myelin. It is becoming clear that the electrophysiologic aspects of these disorders are more complex than previously realized. We review the current information available on the electrophysiologic features of the inherited demyelinating neuropathies in hopes of clarifying the clinical electrodiagnostic features of these disorders as well as to shed light on the physiologic consequences of the different genetic mutations.