Maurice R. Hanson

Chloroquine neuromyotoxicity. Clinical and pathologic perspective.

Six cases of toxic myopathy and/or neuropathy with chloroquine and/or hydroxychloroquine therapy are described. Two patients had unique clinical and pathologic evidence of cardiomyopathy secondary to chloroquine or hydroxychloroquine therapy. One patient had polyneuropathy secondary to chloroquine toxicity. This may be the first documentation of several features of chloroquine/hydroxychloroquine toxicity: morphologic changes in human peripheral nerve in chloroquine toxicity; chloroquine/hydroxychloroquine cardiomyopathy diagnosed by endomyocardial biopsy; and hydroxychloroquine myotoxicity. Chloroquine is a neuromyotoxin that affects nerves and cardiac and skeletal muscles. Discontinuation of chloroquine and hydroxychloroquine resulted in marked improvement in most cases. The reversibility of the symptoms emphasizes the importance of recognizing potential signs of nerve, muscle, and cardiac toxicity in patients being treated with chloroquine or hydroxychloroquine.

Ischemic optic neuropathy A complication of cardiopulmonary bypass surgery

Ischemic optic neuropathy followed cardiopulmonary bypass surgery in the postoperative period in 7 of 7685 consecutive procedures. The visual loss was unilateral in four patients and bilateral in three and there was little improvement. This ischemic infarction of the optic nerve disk was attributed to hypotension, hypothermia, and activation of certain complement factors by the bypass procedure.

Amyotrophic lateral sclerosis Effects of acute intravenous and chronic subcutaneous administration of thyrotropin‐releasing hormone in controlled trials

We performed double-blind crossover trials to assess the effects of thyrotropin-releasing hormone (TRH) on amyotrophic lateral sclerosis patients. For acute intravenous trials, 500 mg TRH or placebo with norepinephrine was given at 1-week intervals (16 patients). CSF TRH concentration increased, and clinical side effects appeared with TRH. For chronic studies, 25 mg TRH and a saline placebo were given subcutaneously every day for 3 months (25 patients). CSF TRH level increased 29-fold after a single TRH injection, and mild transient side effects occurred. Vital signs, respiratory function, semiquantitative and quantitative neurologic function, muscle strength by manual and dynamometer testing, and EMG were studied. With daily TRH, 10 patients noted subjective improvement without objective evidence, and 10 patients complained of worsening of the disease with objective decline after TRH was stopped. Statistical analysis, however, showed no beneficial effects from either acute or chronic TRH trials.

Mechanism and Frequency of Brachial Plexus Injury in Open-Heart Surgery: A Prospective Analysis

A computer-assisted prospective analysis of 531 patients undergoing open-heart operations revealed that 26 patients (5%) sustained brachial plexus injury. In 22 of the 26 patients (85%), the lesion involved the lower trunk or C8-T1 nerve roots. Electromyograms confirmed the clinical impression in 13 patients. In 19 of the 26 patients (73%), the side on which the plexus lesion was found correlated with the side of internal jugular vein cannulation. Because of the anatomical proximity of the lower trunk to the internal jugular vein and the preponderance of lower trunk lesions, we postulate that traumatic cannulation may be a major mechanism of plexus injury. Thus, the resulting syndrome of pain, dysesthesias, and hand weakness may sometimes be preventable.

Pudendal neuropathy in evacuatory disorders

PURPOSE: Aims of the present study were to assess frequency of pudendal neuropathy in patients with constipation and fecal incontinence, to determine its correlation with clinical variables, anal electromyographic assessment, and anal manometric pressures, and to determine usefulness of the pudendal nerve terminal motor latency assessment in evaluation of these evacuatory disorders. METHODS: From 1988 to 1993, 395 patients (constipated, 172; incontinent, 223) underwent pudendal nerve terminal motor latency, electromyography, and anal manometry. Pudendal neuropathy was defined as a pudendal nerve terminal motor latency greater than 2.2 ms. RESULTS: Patients were a mean age of 60.7 (range, 17–88) years. Overall incidence of pudendal neuropathy was 31.4 percent (constipated, 23.8 percent; incontinent, 37.2 percent;P<0.05). Incidence of pudendal neuropathy dramatically increased after 70 years of age in both groups (22 percentvs.44 percent;P<0.05). Moreover, subjects with pudendal neuropathy were older than those without pudendal neuropathy (mean age, 67vs.57 years;P<0.05). The presence of pudendal neuropathy was associated with decreased motor unit potentials recruitment in patients with incontinence (P<0.01). Patients with and without pudendal neuropathy had a similar mean squeezing pressure in both groups. CONCLUSION: Pudendal neuropathy is an age-related phenomenon. Although pudendal neuropathy is associated with abnormal anal electromyographic findings in patients with incontinence, no association with anal manometric pressures was found. Pudendal nerve terminal motor latency assessment is a useful tool in the evaluation of patients with fecal incontinence, but its role in the assessment of constipated patients remains unknown.

Neuro‐ophthalmologic complications of cardiac catheterization

We examined ten patients who, from 1981 to 1986, sustained neuro-ophthalmologic events during cardiac catheterization. Eight patients, most of whom recovered, were believed to have sustained embolic phenomena. Two patients experienced a typical migraine during the catheterization and likewise did well. We conclude that the likelihood of sustaining a neuro-ophthalmic complication during cardiac catheterization is low and that the prognosis after having sustained such a complication is generally favorable. Evidence suggests that artery-to-artery emboli is the dominant pathogenic factor.

Pattern evoked potentials (PEPs) in parkinson’s disease

Controversy exists in the literature concerning whether Parkinsons disease (PD) results in prolongation of pattern evoked potential (PEP) responses. PEPs were obtained in 20 patients with PD. The latencies of the first major positive potential (P2) in response to independent left and right eye stimulation were evaluated. There was no statistically significant difference (group or individual) when patients with PD were compared with age-corrected controls. There was no difference in results in comparing patients with mild, moderate, and severe PD. These results contradict previous reports of markedly abnormal PEPs.

Role of pudendal nerve terminal motor latency assessment in constipated patients

The importance of pudendal nerve terminal motor latency assessment for the evaluation of incontinence is well established. However, its role in constipated patients remains unclear. PURPOSE: The purpose of the present study was to assess the incidence of pudendal neuropathy in constipated patients and its correlation with others variables including age, sex, anal pressures, and anal electromyography. RESULTS: From 1988 to 1993, 161 patients with chronic constipation underwent pudendal nerve terminal motor latency assessment, anal electromyography, and anal manometry. The overall incidence of pudendal neuropathy was 23.6 percent; females and males had a similar incidence (24 percentvs. 23 percent, respectively;P >0.05). Patients over 70 years old had a significantly higher incidence of pudendal neuropathy than did patients under 70 years (37 percentvs. 12 percent, respectively;P<0.01). Patients with paradoxical puborectalis contraction on anal electromyographic assessment had a higher incidence of bilateral neuropathy, paradoxical puborectalis contraction (+)23 percentvs. paradoxical puborectalis contraction (−)8 percent,P<0.05. Patients with pudendal neuropathy also had a higher incidence of decreased motor units potential recruitment than did patients without pudendal neuropathy (31.5 percentvs. 17 percent, respectively;P>0.05). CONCLUSIONS: Pudendal nerve terminal motor latency assessment was able to detect unsuspected pudendal neuropathy in 24 percent of patients. This finding correlated with age and with the presence of paradoxical puborectalis contraction but not with manometric anal pressures, motor unit potentials recruitment, or the presence of polyphasia. However, the often espoused relationship between pudendal latency and external sphincter function could not be demonstrated.

Surgical treatment of compressive cervical band.

Compression of the lower portion of the brachial plexus by a cervical band continuous with the scalenus medius is a rare but well-defined cause of arm pain. The syndrome should be suspected in a patient who presents with chronic arm pain and thenar atrophy. Cervical ribs or prominent C-7 transverse processes will be present on an anteroposterior roentgenogram of the cervical spine, and the diagnosis is confirmed by characteristic electromyographic findings. The syndrome should be differentiated from other causes of chronic arm pain, such as herniated cervical disc, syringomyelia, spinal cord tumor, or carpal tunnel syndrome. The condition is readily treated by surgical division of the compressive band, approached through a supraclavicular incision.

Amlodipine for Migraine Prophylaxis

Migraine is among the most common neurologic disorders encountered in clinical practice.1 In the general US population, the annual incidence has been calculated to be approximately 250 per 100 000 with a point prevalence of 10%.2 Females are affected more than males. A variety of prophylactic and abortive medications are being used for treatment and several are being studied in clinical trials. Calcium‐channel blockers are frequently used prophylactic medications. We report two patients with migraine successfully treated with amlodipine (Norvasc, Pfizer, Inc), a slow calcium‐channel blocker. To our knowledge, these are the first reported cases of amlodipine used in migraine prophylaxis.