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Biomedical subjects

E L Logigian

Publications and source records attributed to E L Logigian.

At least 73 records · Page 4Linked to original sources
PubMed1994

Nerve conduction and biopsy correlation in over 100 consecutive patients with suspected polyneuropathy.

Neuropathy was classified physiologically and histologically as normal, axonal, demyelinative, or indeterminate using specific motor nerve conduction (NC) and sural sensory nerve biopsy (NB) criteria. Physiological and histological diagnoses were concordant in 63%, and minimally discordant in 14% of patients. The most important discordant patients were 6 with demyelinative neuropathy, 4 by NC, of which 2 were pure motor syndromes, and 2 by NB, both predominantly sensory syndromes. In the 55 patients with predominant axonal degeneration on biopsy, the extent of NC slowing was determined. As compound motor and sensory nerve action potential (CMAP and SNAP) amplitude declined, distal motor latency increased, whereas motor and sensory conduction velocity (CV) did not. Minimum F response latency increased as motor CV decreased, more in lower than upper extremity nerves. We conclude that: (1) except for sensory neuropathy, routine motor NC studies generally suffice in identifying demyelinative neuropathy; (2) NC slowing in axonal neuropathy is usually slight but may result in significantly prolonged distal motor latencies when CMAP amplitude is very low, and prolonged F wave latency when motor CV is slightly low; and (3) The physiologic criteria employed in this study rarely misclassifies neuropathy as demyelinative in patients with predominant axon loss on biopsy.

Action Potentials↗
PubMed1993

The overdiagnosis of Lyme disease.

OBJECTIVE: To analyze the diagnoses, serological test results, and treatment results of the patients evaluated in a Lyme disease clinic, both prior to referral and from current evaluation. DESIGN: Retrospective case survey of prescreened patients. SETTING: Research and diagnostic Lyme disease clinic in a university hospital. PATIENTS: All 788 patients referred to the clinic during a 4.5-year period who were thought by the referring physician or the patient to have a diagnosis of Lyme disease. MAIN OUTCOME MEASUREMENTS: Symptoms and signs of disease, immunodiagnostic tests of Lyme disease, and tests of neurological function. RESULTS: Of the 788 patients, 180 (23%) had active Lyme disease, usually arthritis, encephalopathy, or polyneuropathy. One hundred fifty-six patients (20%) had previous Lyme disease and another current illness, most commonly chronic fatigue syndrome or fibromyalgia; and in 49 patients, these symptoms began soon after objective manifestations of Lyme disease. The remaining 452 patients (57%) did not have Lyme disease. The majority of these patients also had the chronic fatigue syndrome or fibromyalgia; the others usually had rheumatic or neurological diseases. Of the patients who did not have Lyme disease, 45% had had positive serological test results for Lyme disease in other laboratories, but all were seronegative in our laboratory. Prior to referral, 409 of the 788 patients had been treated with antibiotic therapy. In 322 (79%) of these patients, the reason for lack of response was incorrect diagnosis. CONCLUSIONS: Only a minority of the patients referred to the clinic met diagnostic criteria for Lyme disease. The most common reason for lack of response to antibiotic therapy was misdiagnosis.

Adolescent↗
PubMed1993

Relationship between stimulus strength and the cutaneous silent period.

During sustained muscle contraction, an interval of reduced activity follows an electrical cutaneous stimulus, called the cutaneous silent period (CSP). To evoke a CSP, a single stimulus must be painful. We used single sural nerve stimuli to evoke a CSP in ipsilateral soleus muscle, and studied the relationships between stimulus strength, sensory action potential (SAP) morphology, and subjective experience. Near nerve electrodes were employed to record the sural SAP in order to record activity in slower conducting fibers in addition to A alpha fibers. In 6 normal subjects, the stimulus strength required to evoke a CSP ranged from 8 to 10 times threshold intensity. Pain threshold was slightly below that necessary to evoke the CSP. SAP shape changed with stimulus strength; main component amplitude occasionally increased as strength increased beyond 10 times threshold, and slowly conducting late components became more prominent. At stimulus intensities or at less than CSP threshold, components were seen conducting from 15-20 m/s that were not observed at lower intensities. We suggest that activation of sensory axons with conduction velocities in the range of A delta fibers are necessary to evoke the CSP, and that their potentials can be discerned in the SAP.

Action Potentials↗
PubMed1993

Acute Lyme neuropathy presenting with polyradicular pain, abdominal protrusion, and cranial neuropathy.

A 53-year-old man developed multifocal radicular pain. The diagnosis of Lyme neuroborreliosis was delayed until bifacial paresis and right lower abdominal wall weakness developed, prompting further evaluation. Cerebrospinal fluid (CSF) examination showed aseptic meningitis. Antibodies directed against Borrelia burgdorferi were present in the serum; higher titers were present in the CSF, indicating local antibody production. Electrophysiologic studies showed both an axonal polyradiculopathy as well as demyelinative facial palsy. Ceftriaxone therapy led to marked improvement in pain and facial palsies.

Electromyography↗
PubMed1993

Nonvasculitic, steroid-responsive mononeuritis multiplex.

We report two patients with mononeuritis multiplex, both of whom had focal inflammation of the perineurium and endoneurium on sural nerve biopsy without necrosis of blood vessel walls, histologic evidence of lymphoid malignancy, or mycobacterial infection. The predominant early sensory symptoms were asymmetric pain and paresthesias; subsequently, muscle weakness developed. Electrophysiologic studies showed an asymmetric sensorimotor axon loss radiculoneuropathy with denervation of limb and paraspinal muscles. Spinal fluid protein was elevated in one patient. There was no cause or underlying systemic disease. Marked improvement occurred with steroid therapy.

Action Potentials↗
PubMed1992

Lumbrical and interossei recording in carpal tunnel syndrome.

Median motor studies are commonly "normal" in mild carpal tunnel syndrome (CTS). This reflects either the sparing of motor compared to sensory fibers, or the inability of conventional studies to detect an abnormality. A novel approach to demonstrate early motor fiber involvement in CTS is the placement of the same active electrode lateral to the third metacarpal, allowing recording from the second lumbrical or the deeper interossei, when stimulating the median or ulnar nerves at the wrist, respectively. We compared the difference between these latencies in 51 normal control hands to 107 consecutive patient hands referred with symptoms and signs suggestive of CTS, who were subsequently proven to have electrophysiologic CTS by standard nerve conduction criteria. A prolonged lumbrical-interossei latency difference (> 0.4 ms) was found to be a sensitive indicator of CTS in all patient groups. It was also helpful in patients with coexistent polyneuropathy, where localization at the wrist was otherwise difficult.

Adult↗
PubMed1992

Clinical and electrophysiologic findings in chronic neuropathy of Lyme disease.

We evaluated 25 patients with Lyme disease and chronic peripheral neuropathy. All had immunologic evidence of exposure to Borrelia burgdorferi and no other identifiable cause of neuropathy. Neuropathic symptoms began a median of 8 months (range, 0 to 165) after erythema migrans and had been present for a median of 12 months (range, 2 to 168) prior to evaluation. Twelve patients (48%) had generally symmetric distal, nonpainful paresthesia, and another 12 (48%) had generally asymmetric radicular pain. One patient (4%) had asymptomatic neuropathy. The most common physical finding was multimodal sensory loss, which was observed in 13 patients (52%); weakness and hyporeflexia were less common. Motor or sensory nerve conduction was slightly slow in 16 patients (64%). The paresthesia group more often had abnormalities on physical examination and on nerve conduction testing than did the radicular group. In 75% to 80% of patients from both groups, however, needle examination showed denervation in paraspinal and limb muscles. Among 20 patients who underwent lumbar puncture, only one had a slight spinal fluid pleocytosis. Six months after treatment with intravenous ceftriaxone, 19 patients (76%) were clinically improved. We conclude that Lyme disease can be associated with a reversible, mild chronic axonal sensorimotor polyradiculoneuropathy or polyradiculopathy.

Adult↗
PubMed1992

Memory impairment and depression in patients with Lyme encephalopathy: comparison with fibromyalgia and nonpsychotically depressed patients.

Lyme encephalopathy, primarily manifested by disturbances in memory, mood, and sleep, is a common late neurologic manifestation of Lyme disease. We compared 20 patients with Lyme encephalopathy with 11 fibromyalgia patients and 11 nonpsychotically depressed patients using the California Verbal Learning Test, Wechsler Memory Scale, Rey-Osterrieth Complex Figure Test, Minnesota Multiphasic Personality Inventory (MMPI), and Beck Depression Inventory. Compared with patients with fibromyalgia or depression, the Lyme encephalopathy group showed mild, but statistically significant, memory deficits on two of the three memory tests. In contrast, the patients with fibromyalgia scored significantly higher than both other groups on the MMPI scale most sensitive to somatic concerns (scale 1), while the depressed patients scored higher than the Lyme patients on the scales most sensitive to depression (scale 2) and anxiety (scale 7). Physical complaints and depression were not major factors in memory performance among Lyme patients. These data support the hypothesis that Lyme encephalopathy is caused by CNS dysfunction and cannot be explained as a psychological response to chronic illness.

Adult↗
PubMed1991

Abnormal most-rapid isometric contractions in patients with Parkinson's disease.

Fast isometric elbow flexor muscle contractions of specified amplitude in six normal subjects were compared with those of 11 patients with Parkinson's disease. Despite treatment, all patients exhibited deficits in this motor task. Three patients were able to produce rapid force pulses with normal contraction times, but the variability of their force responses was increased in comparison with the highly stereotyped responses produced by normal subjects. The other eight patients had prolonged contraction times and segmentation of the force profiles. The integrated area of the first agonist EMG burst and the rate of development of force (dF/dt) were less at any target level than what was needed to produce a fast response. The area of the EMG burst, however, did increase with target amplitude, and the relative increase of dF/dt, with target amplitude, was normal. It is concluded that the motor program subserving fast muscle contraction is preserved in Parkinson's disease, but its execution is characterised by improper scaling of motor output.

Adult↗
PubMed1990

Chronic neurologic manifestations of Lyme disease.

BACKGROUND AND METHODS: Lyme disease, caused by the tick-borne spirochete Borrelia burgdorferi, is associated with a wide variety of neurologic manifestations. To define further the chronic neurologic abnormalities of Lyme disease, we studied 27 patients (age range, 25 to 72 years) with previous signs of Lyme disease, current evidence of immunity to B. burgdorferi, and chronic neurologic symptoms with no other identifiable cause. Eight of the patients had been followed prospectively for 8 to 12 years after the onset of infection. RESULTS: Of the 27 patients, 24 (89 percent) had a mild encephalopathy that began 1 month to 14 years after the onset of the disease and was characterized by memory loss, mood changes, or sleep disturbance. Of the 24 patients, 14 had memory impairment on neuropsychological tests, and 18 had increased cerebrospinal fluid protein levels, evidence of intrathecal production of antibody to B. burgdorferi, or both. Nineteen of the 27 patients (70 percent) had polyneuropathy with radicular pain or distal paresthesias; all but two of these patients also had encephalopathy. In 16 patients electrophysiologic testing showed an axonal polyneuropathy. One patient had leukoencephalitis with asymmetric spastic diplegia, periventricular white-matter lesions, and intrathecal production of antibody to B. burgdorferi. Among the 27 patients, associated symptoms included fatigue (74 percent), headache (48 percent), arthritis (37 percent), and hearing loss (15 percent). At the time of examination, chronic neurologic abnormalities had been present from 3 months to 14 years, usually with little progression. Six months after a two-week course of intravenous ceftriaxone (2 g daily), 17 patients (63 percent) had improvement, 6 (22 percent) had improvement but then relapsed, and 4 (15 percent) had no change in their condition. CONCLUSIONS: Months to years after the initial infection with B. burgdorferi, patients with Lyme disease may have chronic encephalopathy, polyneuropathy, or less commonly, leukoencephalitis. These chronic neurologic abnormalities usually improve with antibiotic therapy.

Adult↗
PubMed1990

Neurophysiology of fastest voluntary muscle contraction in hereditary neuropathy.

In patients with hereditary motor and sensory neuropathy types I (demyelinative) and II (neuronal) and in normal subjects, isometric force and electromyographic activity of the first dorsal interosseous muscle were recorded during fastest voluntary contractions and during twitches evoked by nerve stimulation. The maximum voluntary force of the first dorsal interosseous muscle was also measured. In patients, fastest voluntary contraction time (i.e., time from onset of contraction to peak force) was prolonged and inversely proportional to maximum voluntary force. Maximum rate of rise of tension (i.e., slope of rise in force) was reduced and directly proportional to maximum voluntary force. In patients with hereditary motor and sensory neuropathy type I, contraction time was longer and the maximum rate of rise of tension was lower than in those with hereditary motor and sensory neuropathy type II. In patients and normal subjects, voluntary contraction time was closely correlated with the duration of electromyographic bursts. In patients, the twitch contraction time was prolonged and inversely proportional to maximum voluntary force. Twitch contraction amplitude was diminished and directly proportional to maximum voluntary force. Neither twitch contraction time nor amplitude were dependent on the type of hereditary motor and sensory neuropathy. Twitch contraction time evoked by proximal nerve stimulation was minimally longer than that evoked by distal stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

The accuracy of bedside neurological diagnoses.

The accuracy of bedside diagnoses was prospectively studied in 100 consecutive patients admitted to the neurology service at New England Medical Center, Boston. Each patient was evaluated independently by a junior resident, a senior resident, and a staff neurologist, who were required to make an anatomical and etiological diagnosis based solely on the history and physical examination. Fourteen patients were excluded because their diagnoses were known before admission. Of the remaining 86 patients, it was possible to confirm anatomical and etiological diagnoses in 40 by matching the clinical syndromes with highly specific laboratory findings. In the other 46 patients, the diagnoses could not be confirmed because the laboratory studies (including magnetic resonance imaging) were negative or nondiagnostic. In the 40 patients with laboratory confirmed final diagnoses, the clinical diagnoses of the junior residents, senior residents, and staff neurologists were correct in 26 (65%), 30 (75%), and 31 (77%), respectively. There was a trend for error rates to be higher among junior residents than staff (p = 0.06). The errors by the junior residents, [senior residents], (staff) were attributed to incomplete history and examination in 4 [1] (0), inadequate fund of knowledge in 4 [3] (3), and poor diagnostic reasoning in 6 [6] (6). These results indicate that technology is not a panacea for our diagnostic difficulties and that there is room for improvement in our clinical skills, especially diagnostic reasoning.

Adult↗
PubMed1990

Evaluation of the intrathecal antibody response to Borrelia burgdorferi as a diagnostic test for Lyme neuroborreliosis.

The intrathecal antibody response to Borrelia burgdorferi was evaluated in American and West German patients with Lyme neuroborreliosis. By an antibody capture enzyme immunoassay, 12 (92%) of 13 patients from the USA with Lyme meningitis were found to have intrathecal antibody production to B. burgdorferi, usually of multiple isotypes, most commonly IgA. Of 12 patients with putative late central nervous system manifestations of Lyme disease, 5 (42%) had local production of IgG or IgA spirochetal antibody, but cerebrospinal fluid (CSF) abnormalities could not be demonstrated in 6 patients with late peripheral nervous system manifestations of the disorder. Compared with American patients, 30 European patients with neuroborreliosis had significantly higher CSF:serum ratios of specific antibody both early and late in the illness. Intrathecal antibody determinations are the most specific diagnostic test currently available for Lyme neuroborreliosis, but local antibody production in CSF is an inconsistent finding in American patients with late neurologic manifestations of the disorder.

Antibodies, Bacterial↗