Nerve entrapment syndromes.

Peripheral nerve entrapment syndromes may be caused by inflammation, trauma, or congenital deficits. Some entrapment neuropathies are overdiagnosed, particularly carpal tunnel syndrome. Other nerve entrapment syndromes, such as the thoracic outlet syndrome, posterior interosseous nerve syndrome, and anterior interosseous nerve syndrome, are rare. In most cases of an entrapment neuropathy, the diagnosis and management are straightforward, but much remains to be learned about the natural history, course, and prevention of these clinical conditions.

Peripheral nerve entrapments, repetitive strain disorder, occupation-related syndromes, bursitis, and tendonitis.

Physiologically, peripheral nerve entrapments show focal slowing, and histologically, segmental demyelination and remyelination occur. Entrapment neuropathies result from direct mechanical injury (eg, chronic low pressure or friction in the carpal tunnel syndrome). Compartment syndromes occur when locally increased pressure within a closed muscle compartment compromises local circulation and neuromuscular function. Perioperative nerve lesions result from acute trauma to susceptible individual nerves during surgical procedures. Overuse syndromes belong to the broad clinical group of repetitive strain disorders, and are injuries caused by cumulative effects on tissues of repetitive physical stress that exceeds physiologic limits (eg, occupation-related focal nerve compressions in certain musicians). Current utilization of neurophysiologic electrodiagnostic studies and neuroimaging technology, such as magnetic resonance imaging, facilitates diagnosis and appropriate therapy in many of the disorders mentioned in this paper.

An overview of stroke. Epidemiology, classification, risk factors, clinical aspects.

Although evidence indicates that the incidence of stroke has declined over the past 30 years, stroke remains one of the leading causes of disability and death in the United States. Prevention appears to be the best treatment. According to the Straub Stroke Registry, 52% of strokes in its patient population can be attributed to a thrombotic mechanism. Besides thrombosis, the major causes of stroke are embolism, lacunar infarct, cerebellar infarction, and hemorrhage. Hypertension is a widely recognized risk factor for stroke, but the risks vary for each type of stroke. Transient ischemic attacks may precede stroke and thus are a warning signal. Since acute stroke cannot be cured, management includes symptomatic care and control of related problems such as hypertension. Carotid endarterectomy is useful in prevention of initial or recurrent stroke. The prognosis of stroke patients varies depending on the size of the lesion.

The cervical myelopathy associated with rheumatoid arthritis: analysis of patients, with 2 postmortem cases.

The clinical findings in a group of 32 rheumatoid patients with symptomatic myelopathy are described. The myelopathy appeared in late middle age after many years of rheumatoid disease (average duration, 18 years). The most common radiological abnormality was anterior subluxation of C1. Other patterns occurred in about half the cases. The most common neurological findings were those of a mild to moderate spastic paraplegia, often with atrophy of muscles of the hands and sensory changes in the hands. Symptoms originating above the foramen magnum (nystagmus, diplopia, slurred speech) appeared to have a vascular cause and were sometimes associated with upward as well as posterior movement of the odontoid process. Root pain into the arms was not present, and its absence helped to distinguish these disorders from cervical spondylosis. Root pain into the territory of the C2 root was common. Medical or conservative therapy was not effective, and the preferred approach was use of a halo traction device followed by posterior fusion, with or without laminectomy. Pathologically, in 2 autopsy cases, the maximal change had occurred in the central gray matter and adjacent posterior and lateral columns. We postulate that direct pressure caused intermittent compression and narrowing of distal transverse branches of the anterior spinal artery.

Anterior interosseous nerve syndromes. Diagnostic methods and alternative treatments.

Electromyographic and nerve conduction studies on 46 normal controls (12 men and 34 women, aged 9 to 67 years) are compared with findings in seven patients (three men and four women, aged 9 to 60 years) with the anterior interosseous nerve (AIN) syndromes, including two patients with bilateral involvement (the first such reported cases, to our knowledge). Routine motor and sensory nerve conduction studies of the radial, median, and ulnar nerves show no difference between controls and patients. In 46 normal controls (84 different AIN studies), the latency and duration of the evoked action potential from elbow to pronator quadratus was 5.1 msec +/- 0.9 (95% confidence interval) and 3.6 msec +/- 1.1 (95% confidence interval), respectively. Five of the seven patients had abnormal latencies from elbow to pronator quadratus while all showed prolonged duration of the action potential. Electromyographic abnormalities of the pronator quadratus, flexor pollicis longus, and flexor digitorum profundi, as well as delayed motor latencies and prolonged duration of the evoked potential of the AIN from elbow to pronator quadratus provide sufficient information to diagnose the AIN syndrome. Surgical exploration may not be necessary unless there is evidence of a penetrating injury, significant entrapment, or certain fractures.

Duane syndrome and congenital upper-limb anomalies. A familial occurrence.

We report a family in which five members in three generations have been afflicted with Duane syndrome. Four of the five members also have congenital hypoplasia of the thenar eminence. One also was afflicted with Hirschsprung disease and another was born deaf. A sixth member, who does not have Duane syndrome, is afflicted with a more extensive malformation of the upper extremities and unilateral deafness. We present a discussion of Duane syndrome and its association with other congenital anomalies. Although some members of this family presented in this report show features that are similar to the Holt-Oram syndrome, Wildervanck's syndrome, and others reported in the literature, there are several unique features about this family that we thought were worth reporting.

Mortality among rubber workers. I. White male union employees in Akron, Ohio.

Mortality among a cohort of 13,571 white male rubber workers in Akron, Ohio is described. Mortality from all causes was 82% of that expected on the basis of death rates for US white males. Excess deaths from cancer (observed/expected numbers) in specific sites among workers in specific work areas include stomach:processing (18/9.9); large intestine: processing (14/10.5); lung: tire curing (20/12.4): bladder: all workers (48/39.5); brain: tire building (7/3.7): lymphatic: tire building (11/7.1): and leukemia: all workers (55/43.0). In general, excess cancer deaths occurred most often among men who started working between ages 35 and 44 and prior to 1935, who worked 25-34 years and were over age 74 at death, and who died after 1954.

Mortality among rubber workers. II. Other employees.

Mortality among female, black male and white male salaried employees in Akron, Ohio, is described. Standard mortality ratios for all causes of death are: females, 78: black males, 62: white salaried males, 65. Excess deaths from cancer occurred in females: uterus, bladder, brain and multiple myeloma; in black males: Hodgkin's disease; and in white salaried males: bladder and lymphatic. Also, proportional mortality among white male employees of six non-Akron plants is reported. Excess deaths from cancer include brain and lymphatic and hematopoietic.