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Biomedical subjects

P Tsairis

Publications and source records attributed to P Tsairis.

At least 19 recordsLinked to original sources
PubMed1999

Brachial neuritis.

Brachial neuritis is a rare disorder of unknown etiology that causes pain and weakness of the shoulder and upper extremity. There have been many descriptions of the disorder in the literature. The classic symptoms begin with an acute onset of sharp pain in the shoulder girdle. As the pain subsides, weakness occurs. The diagnosis often is difficult to make in the acute setting. Diagnostic tests typically are not helpful, although electromyography may be useful. The treatment is chiefly supportive with analgesics initially followed by range of motion exercises. Full functional recovery is expected in most patients, although the interval may be protracted. Understanding the disorder of brachial neuritis and its course will assist in the diagnosis and treatment.

Brachial Plexus Neuritis↗
PubMed1996

Spontaneous thoracic spinal cord herniation. A case report.

STUDY DESIGN: This is a case report. OBJECTIVE: To focus attention on spontaneous spinal cord herniation as a rare cause of myelopathy that can be diagnosed preoperatively and can be corrected surgically. SUMMARY OF BACKGROUND DATA: A 34-year-old woman presented with spastic paraparesis. Magnetic resonance imaging scan of the thoracic spine revealed anterior displacement and tethering of the cord at T6-T7 and a dorsal intradural arachnoid cyst. Excision of the cyst was performed without improvement in symptomatology. During reoperation the thoracic spinal cord hernia was discovered and was reduced intradurally. METHODS: The authors describe the clinical, radiographic, and surgical findings of this patient and review the findings from other reported cases. They discuss the proposed theories for the pathophysiology of the cord herniation and the surgical management. RESULTS: The patient had idiopathic thoracic spinal cord herniation as there was no history of previous spine surgery or injury. The authors believe that the cord herniated through a congenital dural defect, which resulted in the development of a pseudoarachnoid cyst dorsally to the hernia. The patient improved after intradural reduction of the hernia and closure of the dural defect. CONCLUSION: Idiopathic spinal cord herniation should be recognized as a cause of progressive myelopathy that can be managed successfully with microsurgical techniques.

Adult↗
PubMed1996

Myoglobinuria due to quail poisoning.

Quail poisoning is known to produce an acute myoglobinuric syndrome. The cause of this syndrome is still unknown. It has been suggested that a toxic effect or a genetic sensitivity plays a major role. Ten patients with a history of quail poisoning were examined to determine their present state and the course of the disease. A muscle biopsy was performed in 2 of these patients who complained of muscle cramps after exercise. The activities of several glycolytic mitochondrial and lipolytic enzymes were estimated. In all 10 patients the physical examination, electromyogram findings and conduction velocities were normal. Serum levels of CK, aldolase and lactic acid were also within normal range. In the 2 patients with cramps, all enzyme activities were normal in muscle tissue. Our findings possibly exclude a preexisting enzyme defect as a cause of myoglobinuria in quail poisoning. Considering that 4 of our patients continued the consumption of quails without further problems, we suggest that the major factor contributing to quail poisoning must be toxic.

Adolescent↗
PubMed1992

CT of 338 active professional boxers.

Computed tomography (CT) was performed in 338 active professional boxers. CT scans were abnormal in 25 boxers (7%). The most common CT abnormality was brain atrophy (22 cases). Focal lesions of low attenuation consistent with posttraumatic encephalomalacia were noted in only three boxers. Boxers with abnormal CT scans did not differ from those with borderline or normal CT scans in regard to age, win-loss record, number of bouts, or history of an abnormal electroencephalogram. Thirty-seven boxers with borderline CT scans (49%) and 17 with abnormal CT scans (68%) reported a previous technical knockout (TKO) or knockout (KO), compared with only 89 (37%) of the 238 boxers with normal CT scans (P < .01). Brain atrophy was noted more frequently in boxers with a large cavum septum pellucidum (CSP) than in those with a small or no CSP (P < .05). Boxers with abnormal or borderline CT scans who experienced a TKO or KO were slightly older than those with normal CT scans and a history of a TKO or KO (P < .05).

Adolescent↗
PubMed1985

Cross-reinnervated motor units in cat muscle. II. Soleus muscle reinnervated by flexor digitorum longus motoneurons.

The properties of whole soleus (SOL) muscles and of individual motor units were studied in cats 30-50 wk after self-reinnervation by soleus (SOL) motoneurons (SOL----SOL) or cross-reinnervation by flexor digitorum longus (FDL) motoneurons (FDL----SOL). As in the preceding paper (22), intracellular and glycogen-depletion methods were used to examine the physiological and histochemical properties of individual motor units. The results were compared with data from normal SOL motor units (8, 12). Intentionally self-reinnervated SOL muscles (SOL----SOL; n = 6) were normal in size and wet weight, and all of the five SOL----SOL motor units studied had physiological and histochemical characteristics that matched those of normal SOL units. Cross-reinnervation of SOL by FDL alpha-motoneurons (FDL----SOL; n = 7) produced muscles with wet weights and appearance essentially identical to normal SOL. However, whole-muscle twitch contraction times were much shorter (mean 60.4 ms) than those of normal (mean 136.9 ms, n = 18) or SOL----SOL muscles (mean 115.3 ms; n = 6). Despite this difference, none of the FDL----SOL muscles contained more than 7% histochemical type II muscle fibers, all of which were type IIA. Normal cat SOL muscles can contain up to 5% type IIA fibers, but none of our SOL----SOL muscles showed any type II fibers. Two FDL----SOL muscles had significant amounts of unintended self-reinnervation, permitting side-by-side comparison of FDL----SOL and SOL----SOL muscle fibers. The twitch contraction times of the two populations differed markedly, but they were histochemically indistinguishable except for the fact that SOL----SOL fibers had high neutral fat content (as do normal SOL fibers), whereas FDL----SOL showed much lower fat content. The 23 FDL----SOL muscle units studied were classified as physiological type S by criteria ("sag" test and fatigue resistance) used to identify motor-unit types in normal cat muscles. All five of the FDL----SOL units studied histochemically after glycogen depletion showed the type I histochemical profile, which is characteristic of the normal cat SOL. In marked contrast to the preceding study, cross-reinnervation of cat SOL by FDL motoneurons produced no conversion of muscle-unit properties into those associated with fast-twitch unit types, despite significant decreases in isometric twitch contraction time. The altered twitch speed was not associated with evident changes in conventional myofibrillar adenosine triphosphatase (ATPase) histochemistry.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

Evoked potentials recorded from scalp and spinous processes during spinal column surgery.

Peroneal nerve evoked potentials were simultaneously recorded from scalp and from wire electrodes inserted into lumbar and thoracic spinous processes at multiple levels during surgery for correction of spinal column curvature in 43 patients. Spinal potentials progressively increased in latency rostrally. Over cauda equina and rostral spinal cord initially positive triphasic potentials were recorded. Over caudal spinal cord the response consisted of initial positive-negative diphasic potentials that merged with broad large negative and positive potentials. At rapid rates of stimulation, the initial diphasic component was stable but the subsequent potentials significantly diminished in amplitude. This suggests that the diphasic component reflects presynaptic activity arising in the intramedullary continuations of dorsal root fibers and that the subsequent components reflect largely postsynaptic activity. Scalp recordings at restricted bandpass (30-3000 c/sec) revealed well defined positive and negative potentials with mean peak latencies of 25.9 and 29.9 msec (PV-N1). The amplitudes and latencies of PV-N1 remained relatively stable throughout general anesthesia with halogenated agents which suggests that this component may be a reliable monitor of conduction within spinal cord afferent pathways during spinal surgery. Data are presented which suggest that selective filtering may help to distinguish faster frequency, synchronous axonal events from slower frequency, asynchronous axonal or synaptic events.

Adolescent↗
PubMed1983

Nerve injury in total hip arthroplasty.

The causative factors and the clinical course of symptoms related to nerve injury in total hip arthroplasty were evaluated in 34 patients who underwent surgery during the period from 1969 to 1981. The overall incidence of this complication was 0.6%, with an incidence of 1.0% during the first seven years and of 0.3% during the following six years of the study. Female patients, particularly those with congenital hip dislocation, appeared to be at higher risk of sustaining nerve injury. Pathogenetic mechanisms of nerve injury identified in 47% of the patients included lengthening and/or lateral displacement of the proximal femur, subfascial hematoma formation, prosthetic dislocation, and partial nerve transection. Greater blood loss and longer surgical times were distinguishing features of the nerve injury group as compared with large series of total hip arthroplasties performed during similar periods by the same surgical approaches. Causalgic pain was a significant sequela of nerve injury, and its strong association with bleeding problems was observed. With the exception of causalgic pain, persistent neurologic dysfunction in 79% of these patients at an average of 3.7 years after operation did not cause significant disability.

Adult↗
PubMed1979

Myokymia and impaired muscular relaxation with continuous motor unit activity.

We have studied two cases of the syndrome of myokymia and impaired muscular relaxation with continuous motor unit activity. Both patients complained of muscle twitching, weakness, stiffness, and hyperhydrosis during their illness. Myokymia was present over the entire body in both. On repetitive testing of muscle strength each patient showed initial fatigue followed by increasing strength as he continued his efforts. Both patinets improved on phenytoin therapy at high blood levels. Nerve conduction velocities were decreased. Electromyograms showed continuous electrical activity at rest which persisted during sleep and spinal anaesthesia but was diminished by curare. Intravital staining with methylene blue in one case demonstrated sprouting and beading of motor nerve terminals with multiple innervation of muscle fibres. The neurophysiological and pathological findings in these two cases indicate an abnormality of peripheral nerve in this disorder.

Adult↗
PubMed1979

Rheumatoid meningitis: a localized immune process.

Rheumatoid pachymeningitis is a rare complication of rheumatoid arthritis. This disease was confined to the dura and pia-arachnoid of the lumbar cord in our patient. Her neurologic deficits responded to surgical decompression and corticosteroid therapy. Radiologic evidence and the differences in cell count, protein, and glucose content between lumbar and cisternal cerebrospinal fluid indicate that rheumatoid pachymeningitis can be localized to a discrete region of the central nervous system. Elevated immunoglobulins, IgM and IgG rheumatoid factors, low molecular weight IgM, and immune complexes were found in the cerebrospinal fluid and implicate an immune reaction in the pathogenesis of this disease, which is probably similar to inflammatory processes involving other organs in rheumatoid arthritis.

Aged↗
PubMed1979

Cervical spine fusion in rheumatoid arthritis.

Spinal fusion for deformity of the cervical spine was done in thirty-three patients with rheumatoid arthritis. The average follow-up was three years. The deformities present were atlano-axial subluxation, superior migration of the odontoid process into the foramen magnum, and subaxial subluxation of the vertebral bodies. We devised a classification of the pain and the neural involvement in these patients and a new method of measuring superior migration. The surgical procedures for treating instability, intractable pain, or neural involvement, or a combination of the three, were: (1) a Gallie fusion of the first and second cervical vertebrae for atlanto-axial subluxation, (2) a fusion of the occiput and the second cervical vertebra for superior migration of the odontoid process, and (3) a posterior fusion for subaxial subluxation. The occiput was included in the fusion if superior migration of the odontoid process was demonstrated. The results show that four of five patients who had an anterior fusion had no improvement. Twenty-five patients had posterior fusion; in seventeen the condition was improved, in five there was improvement, and in three the condition was worse. Of nineteen patients with neural involvement, the condition was improved in eight, it was unchanged in seven, and it was made worse in two. There were three postoperative deaths and six additional unrelated deaths within two years of surgery. There were five pseudarthroses.

Adult↗
PubMed1978

Lumbar adhesive arachnoiditis. Etiologic and pathologic aspects.

The etiologic factors and pathologic findings in 38 patients with lumbar arachnoiditis are presented. Lumbar spine surgery and the injection of contrast materials prior to the diagnosis of this condition are considered the most important factors in its genesis. In this series, there was microscopic evidence of arachnoiditis ossificans in 3 patients and arachnoiditis calcificans in 1 patient.

Arachnoid↗
PubMed1978

Effect of compensatory hypertrophy studied in individual motor units in medial gastrocnemius muscle of the cat.

1. Compensatory hypertrophy of the medial gastrocnemius (MG) muscle was produced by denervating or removing its synergists (i.e., the lateral gastrocnemius, soleus, and plantaris muscles) in adult cats. Following survival times of 14-32 wk, intracellular recording and stimulation techniques were used to study the motor-unit population in MG. The data obtained were compared with results from MG motor units in normal unoperated cats of the same body size and weight. 2. Using criteria employed for normal motor units, the units in hypertrophic MG muscles were readily classified into the same groups (types FF, F(int), FR, and S) as in normal MG. There was no detectable difference in the distribution of motor-unit types after hypertrophy. 3. When compared with a normal motor-unit sample, there was a large increase in mean tetanic tension, but no significant change in twitch tension, for each motor-unit type in the hypertrophied muscles. The most marked increase was found among the fatigue-resistant type S and type FR motor units. There was no alteration of twitch contraction times or fatigue resistance in any unit type after hypertrophy. 4. For each motor-unit type, the mean homonymous (MG) group Ia EPSP amplitude was the same in normal and hypertrophic MG populations. There was, however, a significant increase in the average conduction velocity of MG motor axons in the animals with uncomplicated MG synergist removal and maximal MG hypertrophy. 5. On the basis of histochemical staining, muscle fibers from comparable sections of hypertrophic and contralateral (unoperated) MG muscles were presumptively identified as belonging to FF, FR, or S units. There was no significant difference between hypertrophic and contralateral MG muscles in the percentage of each fiber type, although there was some variability in muscle composition from one cat to another. One muscle pair was studied in detail for fiber cross-sectional area. In this cat, with marked hypertrophy by muscle weight, there was a modest increase in the mean fiber areas of histochemical S and FR muscle fibers, but no evident change in FF fibers, on the hypertrophic side. 6. MG motor units were examined in several cats in which synergist removal resulted in scarring and marked limitation of passive ankle mobility, and no evident weight gain in MG. Motor units of all types in these animals showed a decrease in twitch tension and in mean twitch/tetanus ratios, with little alteration in mean tetanic tensions. 7. The main effect of compensatory hypertrophy under the present conditions was a large increase in tetanic tension output from individual motor units due, at least in part, to an increase in fiber cross-sectional area. There was no evidence indicating any "conversion" of motor units or of their muscle fibers from one type to another.

Animals↗
PubMed1977

Thymic lymphocytes in myasthenia gravis.

Lymphocytes from the thymus glands of myasthenic patients and controls were characterized in terms of their percentages of B- and T-cells and their ability to stimulate the proliferation of autologous peripheral blood lymphocytes. Percentages of B- and T-cells were the same in the thymuses of myasthenic and control subjects. Autologous peripheral lymphocyte stimulation by thymocytes was observed in only 1 of 3 myasthenic patients, and this was with a thymus gland containing a thymoma. These results thus differ from those of other investigators.

B-Lymphocytes↗