Correlation between temperature and vibration thresholds and somatosensory evoked potentials

The psychophysically assessed thermal specific, thermal pain and vibration sensitivities were correlated to somatosensory evoked potentials in eighteen patients with definite multiple sclerosis. In the psychophysical tests, modality specific stimuli were used. Somatosensory potentials were electrically evoked. The abnormalities of both the temperature and the vibration sensitivity were to same extent related to the somatosensory evoked potentials. Dorsal columns-medial lemnisc and anterolateral-spinothalamic demyelinating lesions were presumed. The psychophysical tests supplement the clinical, laboratory, neuroradiologic and electrophysiological tests. These should be included in the battery of diagnostic tests in multiple sclerosis.

Subclinical neuropathy in type I diabetic children

OBJECTIVES

Small and large, somatic and autonomic nerve fibre functions were neurophysiologically evaluated in 33 asymptomatic neurologically free type I diabetic children and 69 age-matched healthy controls.

METHODS

The evaluation of large and small somatic nerve fibre function was performed by conventional nerve conduction studies, thermal specific and thermal pain sensitivity tests, as well as autonomic nerve fibre functions by sympathetic skin response and R-R interval variation assessment.

RESULTS

A significant difference was established between the healthy and the diabetic group. Neurophysiologically determined subclinical neuropathy was found in 87% of type I diabetic children. The majority of abnormal recordings were found on the lower limbs. The dysfunction of the somatic motor large nerve fibre type in the lower limbs was altered in 57% of patients, somatic sensory large in 39%, somatic sensory small in 45%, and sympathetic in 45%. The leading abnormal measure was a delayed sympathetic skin response on the foot (42% of diabetic children) followed by a reduced amplitude of sural nerve action potential (36%). The whole spectrum of recordings showed scattered involvement of nerve functions. There was no selective susceptibility of nerve fibre types exposed to a noxious factor.

CONCLUSION

A complex neurophysiological assessment, including standard nerve conduction studies as well as psychophysical examination and autonomic nerve function tests, evaluating the function of small and large nerve fibres, is recommended for evaluating the subclinical neuropathy in asymptomatic type I diabetic children.

[Quantitative determination of the function of thin nerve fibers]

Quantitative assessment of thermal and pain sensitivity (Marstock method on a SOMEDIC Thermotest, Somedic AB Stockholm, Schweden) was made and the function of autonomic nervous system (sympathetic skin response and R-R interval variation) indicating the function of small nerve fibres (A-delta and C) was determined in 44 patients with symptoms of the presumed sensory neuropathy. The function of the large nerve fibres was evaluated by the classic nerve conduction study. The methods of small nerve fibres evaluation exhibited greater sensitivity as the classic nerve conduction study. The dysfunction of small nerve fibre function was morphologically proved by sural nerve biopsy.

Early asymmetric neuropathy in primary Sjögren's syndrome

We report three female patients, 43, 47, and 50 years old, with a rare asymmetric form of clinically pure sensory neuropathy associated with primary Sjögren's syndrome. In all three patients glandular involvement was accompanied by peripheral nerve disease. Sensory conduction studies showed completely normal results in two of three patients. Yet assessment of thermal-specific thresholds and thermal pain thresholds, combined with autonomic function tests (sympathetic skin response and R-R interval variation) supported the clinical suspicion of peripheral nerve disorder. Sjögren's syndrome must be considered in asymmetric sensory neuropathies of unknown cause.

Influence of sympathetic activity, temperature, ischemia and diazepam on thermal and vibration thresholds

In healthy volunteers thermal specific, thermal pain and vibration thresholds were assessed and correlated to each other and to sympathetic nervous system parameters. Additionally, different factors such as temperature, diazepam and ischemia affecting perception thresholds were evaluated. The thresholds assessed did not correlate significantly to each other and to sympathetic skin response latency or amplitude. Diazepam influenced the thermal specific, thermal pain and vibration thresholds assessed. The preingestion and postingestion (after 30, 60 and 90 minutes) thresholds did not differ significantly, meanwhile the scatter of thermal and vibration thresholds increased obviously. The skin temperature within the range of naturally occurring values of control subjects in a state of "thermal comfort" affected neither the warm-cold difference limen nor the heat and cold pain thresholds. Considerable temperature changes (the warming for 5 degrees C and cooling for 10 degrees C) influenced the vibration thresholds measured. Warming increased and cooling decreased the values recorded. Tourniquet-induced ischemia influenced only the vibration disappearance thresholds. Vibration perception and vibration thresholds varied but differences were not significant.

Sympathetic skin response in parkinsonian patients

Sympathetic skin response (SSR) was recorded in 23 patients with idiopathic Parkinson's disease (IPD) using mechanical as well as electrical stimuli. Significant delay of SSR latencies and decrease in amplitude of SSR compared to healthy volunteers were found (p < 0.05). Furthermore the clinical parameters of the autonomic impairment correlated well with the Webster score. Central mechanisms might be responsible for these findings and the role of central sympathetic pathway damage in parkinsonian patients is discussed.

Influence of age, temperature, sex, height and diazepam on vibration perception

Vibration perception was quantitatively examined in 92 healthy volunteers (46 females, 36 males, aged 10-71 years). Vibration perception thresholds, vibration disappearance thresholds and vibration thresholds were assessed at the second metacarpal bone, styloid process of ulna, lateral epicondyle of humerus, first phalanx of the big toe, first metatarsal bone, medial malleolus and proximal part of the tibia bilaterally. Vibration sensitivity was found to be age-dependent. Under the age of 60, the correlation was linear. Vibration thresholds depended on body site but they were not related to sex or body side. Temperature and diazepam affect the perception of vibration considerably. Small interindividual variability was found in measurements repeated in 3 consecutive days, after 4 weeks and after a year.

Botulinum toxin in the treatment of cerebral palsy

This paper reports the results of botulinum toxin A treatment in 13 children with cerebral palsy. All patients except one exhibited dynamic deformities in one hand or foot and changes in muscle tone of corticospinal and extrapyramidal origin. The primary purpose of the treatment was to improve the impaired skilled movements which resulted from dystonic limb posture and were the most disabling symptoms in the group studied. The study showed that the botulinum toxin treatment produced a significant improvement in functional disability in terms of amelioration of skilled hand movements and foot posture (p < 0.01). The injections took effect a few days after dystonic muscle infiltration, and the mean duration of improvement was 3.1 months (2.0-4.0 months). Side effects were negligible and transient; transitory muscle weakness was the most frequent. Botulinum toxin A provides a safe and effective adjuvant treatment of dystonic skilled movements and gait disorders in children with cerebral palsy.

Small nerve fibre dysfunction in a patient with Sjögren's syndrome. Neurophysiological and morphological confirmation

An morphological confirmation of neurophysiologically assessed small nerve fibre dysfunction in a patient with Sjögren's syndrome was sought. Conventional motor and sensory nerve conduction studies were normal, while examination of the thermal specific and thermal pain sensitivity and an autonomic nervous system evaluation showed striking abnormalities. Sural nerve electron microscopy showed almost normally large nerve fibres and abnormalities in unmyelinated nerve fibres or Schwann cells, and verified morphologically the neurophysiologically supposed small nerve fibre involvement.

Quantitative assessment of thermal and pain sensitivity

Values for thermal specific and thermal pain thresholds were determined in 150 healthy volunteers, 67 women and 83 men, aged from 10 to 73 years. Warm-cold difference limen, heat pain and cold pain thresholds were assessed at the face, thenar, medial surface of the upper- and forearm, lateral mammary, lateral umbilical, anterior thigh and lateral leg regions, and lateral aspect of the dorsum of the foot. Temperature and pain sensitivity were assessed by the Marstock method. Temperature sensitivity was found obviously age-dependent. The correlation is linear. Women showed greater sensitivity for small temperature changes, reflected as warm-cold difference limen, and for heat pain and cold pain. Great variation of thermal and pain sensitivity of different body parts was significant in all volunteers, irrespective of age and sex. Interindividual variation was also considerable. Small intraindividual variability was found in measurements repeated in 4 consecutive days and after 4 weeks. Body length did not influence thermal and pain perception thresholds. There were no differences found in thermal and pain sensitivity between the left and the right side of the body.

Neurophysiological assessment of peripheral neuropathy in primary Sjögren's syndrome

Peripheral nervous system complications are rare in patients with primary Sjögren's syndrome. We investigated a group of six women aged 43-64 years who complained of pain and sensory symptoms. Conventional neurophysiological tests reflecting large nerve fiber function revealed normal motor conduction in all patients, whereas sensory nerve action potentials were absent in two. On the other hand, quantitative thermometry and autonomic nerve function tests indicating small nerve fiber function were more sensitive in the assessment of nerve dysfunction; these showed abnormalities in all cases. Vibrametry showed dysfunctions in four patients. The latter methods possess great sensitivity in discovering sensory disturbances. Neurophysiological assessment of the sensory and autonomic nervous system demonstrating sensory neuropathy contributes to early diagnosis of primary Sjögren's syndrome.

Botulinum toxin in the treatment of neurological disorders

Botulinum toxin therapy is safe and effective in the treatment of different movement disorders, especially focal dystonias. We reviewed botulinum toxin treatment of 97 patients: 36 had blepharospasm, 41 had torticollis, and 20 had diverse movement disorders. Patients with blepharospasm and torticollis improved markedly after botulinum toxin injections. The most common side effect in BS patients was ptosis (44.4%); in TC patients, it was dysphagia (29.3%). The mean duration of the improvement in both groups was 3.4 months. Very promising results were obtained also in the heterogeneous group including patients with other focal dystonias and cerebral palsy. On the basis of these results, we concluded that BTA injections must now be considered the mainstay of therapy for focal dystonias and other involuntary movement disorders.

The role of fibrinogen A alpha chains in ADP-induced platelet aggregation in the presence of fibrinogen molecules containing gamma' chains

Human plasma fibrinogen (Fgn) is heterogenous with respect to the size of its gamma chains, which differ in that residues 408 to 411 of gammaA chains (93% of total) are replaced in gamma' chains by a unique 20 amino acid sequence (gamma408 to gamma427). In this study, we compared the contribution to adenosine diphosphate (ADP)-induced platelet aggregation of the A alpha chains in Fgn molecules containing predominantly (fraction 1-2) or exclusively (peak 1 Fgn) gammaA chains with that of molecules containing approximately 50% gamma' chains (peak 2 Fgn). Using washed human platelets, we confirmed that the number of peak 2 Fgn molecules binding to platelets in the presence of ADP was about half the number of peak 1 Fgn molecules (18,962 +/- 2,298 v 44,366 +/- 16,096 molecules per platelet), and that isolated S-carboxymethylated (SCM) gammaA chains supported ADP-induced platelet aggregation nearly as well as peak 1 Fgn. In contrast, SCM-gamma' chains alone supported aggregation poorly, whereas a mixture of SCM-gammaA and gamma' chains (1:1 ratio) gave intermediate results. Despite the findings with isolated SCM-gamma' chains, we found that peak 2 Fgn supported platelet aggregation nearly as well as peak 1 Fgn. However, peak 2 Fgn from which carboxy (COOH)-terminal A alpha chain segments had been removed by digestion with plasmin showed a markedly decreased platelet aggregation potential. Peak 1 Fgn core fraction from an 88% to 90% coagulable plasmin digest, or Fgn fraction 1-9, which has a high gammaA/gamma' chain ratio (93:7), but lacks COOH-terminal regions of A alpha chains, supported platelet aggregation to the same extent as did intact peak 2 Fgn. These findings indicate that Fgn molecules containing gamma' chains can approach the aggregation potential of Fgn molecules containing predominantly or exclusively gammaA chains only if intact A alpha chains are also present.

Evaluation of factor VIII-rich cryoprecipitate and the plasma fibronectin-rich, heparin-precipitable fraction prepared from single-donor plasma units

A plasma fibronectin-rich component was prepared by heparin-induced 4 degrees C precipitation of fresh or stored (21 days at 4 degrees C), single-donor plasma. The recovery of plasma fibronectin was 45 percent at a concentration of 0.05 mg heparin per ml (7.5 units/ml) and 75 percent at 0.1 mg per ml (15 units/ml). The biologic activity of plasma fibronectin, as assessed by the spreading of Chinese hamster ovary cells or attachment of monocytes to gelatin-coated surfaces, was similar to that of plasma fibronectin concentrates made from fresh or stored plasma. Only 20 to 30 percent of the factor VIII activity in fresh plasma was recovered in cryoprecipitate produced after the heparin-induced precipitate containing fibronectin was removed. Cryoprecipitate prepared from the supernatant plasma that remains after heparin-induced cold precipitation in the presence of CaCl2 (5 mM) contained approximately 50 percent less factor VIII. The relatively low recovery of factor VIII in cryoprecipitate prepared from fibronectin-depleted plasma makes cryoprecipitation an unsuitable method of producing fibronectin-rich and factor VIII-rich components effectively from a single unit of fresh plasma. However, heparin-induced cold precipitation provides an efficient method for preparing plasma fibronectin concentrates from small plasma pools or single units of stored or fresh plasma.