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Conduction block in the carpal tunnel syndrome
s94 circuits could disabilities.
be responsible
CONDUCTION DROME.
for the development
of learning
BLOCK IN THE CARPAL TUNNEL SYN-
A. Mclnnes (Western
General
Hospital,
Edinburgh,
UK)
A study was made of conduction block in 150 patients with the carpal tunnel syndrome. The study was performed to assess the degree of damage to the median nerve and to attempt prognosis. Conduction block was assessed in APB and lumbrical muscles (where contrary to previous reports the distal latency was prolonged) and also in the sensory action potentials. Conduction block was found in only 10% of motor studies and 8% of sensory studies. These were found early on in the disease process and prognosis here was excellent. Conduction block was found to explain only a small proportion of the decreased CV of the proximal segment. Slowing of the proximal segment was found to correlate more commonly with the distal latency suggesting an axonopathy with poorer prospects for recovery.
basic physical qualities of resistance to passive stretch. and the presence of other clinical features of diagnostic importance such as bradykinesia, altered posture or extensor plantar rcsponses. This enables rigidity. spasticity, dystonia and hvpotonia to be differentiated. Second. the contribution of abnormal tone to the impairment of voluntary movement can be assessed by a combination of careful clinical observation (such as undertaken by neurological physiotherapists) and recording of clectromyographlc activity under carefully controlled conditions. Third, neurophysiological and biochemical testing can shed light on the pathophysiology of altered muscle tone, sometimes predicting and often illuminating the effects of treatment. In clinical practice. the response of muscle tone to maintained passive stretch or to different drugs is helpful in supporting the clinical diagnosis. However. it is important to recognise that the relationship between tone and voluntary movement IS very complex, and that treatments that reduce muscle rigidity or spasticity can actually cause deterioration in voluntary function.
A TOPOGRAPHIC BRAIN MAPPING APPROACH TO THE STUDY OF ABNORMAL FACIAL MOVEMENTS.
M. Mkdici and L. Crispino
TREATMENT OF ANISMUS BY BIOFEEDBACK. (Hospital A. Mclnnes, (Western
General
Hospital,
Edinburgh,
UK)
Chronic constipation can be a result of anismus or unrelaxed pelvic floor muscles during defaecation. Such constipation can lead to many serious consequences. A measure of anismus using surface electrodes was devised comparing active squeeze with active straiting and found in 40% of patients with idiopathic constipation. These patients were treated with biofeedback using an auditory signal. Following this there was a subjective and objective response in 50-6058 of such patients indicating that this may be a learned response which can be rectified though further studies are required to see if this is maintained.
HOW TO DIFFERENTIATE TONE.
DISORDERS
OF MUSCLE
D. L. McLellan
(University
Italiano,
Montevideo,
Uruguay)
D. Peak, A. Smith and B. Ksimbie
of Southampton,
Southampton,
UK)
Disorders of muscle tone can be differentiated Clinical examination identifies the muscle groups
in 3 ways. involved, the
Topographic brain mapping recordings with backward averaging was performed on 10 patients. Five of them presented essential hemifacial spasm (HFS) and five abnormal facial movements described as tics. The use of backward averaging allowed the detection of a premotor wave associated with voluntary movements and recorded from premotor areas. This voluntary component may be either the only one responsible for the movement or may be related to synkinesis which takes place before, during or after the movement, whether a spasm or a tic. With such a tool we were able to separate abnormal movements into 2 categories: (1) movements associated with a premotor wave and therefore of cortical origin, and (2) movements without a premotor wave, orginating from subcortical structures. The advantages of this procedure lie in the accuracy of diagnosis. This becomes particularly important at the time of choice and initiation of treatment. In the case of HFS for instance, as described in another communication, when voluntary movements appeared as synkinesis, behavioral therapy such as biofeedback is suitable and in many cases movements described as tics have a cortical origin and therefore a voluntary component and behavior therapy or psychotherapy may be indicated. Thus, topographic brain mapping offers the possibility of detecting the true origin of abnormal movements and whether they have a cortical component or not.
be responsible
CONDUCTION DROME.
for the development
of learning
BLOCK IN THE CARPAL TUNNEL SYN-
A. Mclnnes (Western
General
Hospital,
Edinburgh,
UK)
A study was made of conduction block in 150 patients with the carpal tunnel syndrome. The study was performed to assess the degree of damage to the median nerve and to attempt prognosis. Conduction block was assessed in APB and lumbrical muscles (where contrary to previous reports the distal latency was prolonged) and also in the sensory action potentials. Conduction block was found in only 10% of motor studies and 8% of sensory studies. These were found early on in the disease process and prognosis here was excellent. Conduction block was found to explain only a small proportion of the decreased CV of the proximal segment. Slowing of the proximal segment was found to correlate more commonly with the distal latency suggesting an axonopathy with poorer prospects for recovery.
basic physical qualities of resistance to passive stretch. and the presence of other clinical features of diagnostic importance such as bradykinesia, altered posture or extensor plantar rcsponses. This enables rigidity. spasticity, dystonia and hvpotonia to be differentiated. Second. the contribution of abnormal tone to the impairment of voluntary movement can be assessed by a combination of careful clinical observation (such as undertaken by neurological physiotherapists) and recording of clectromyographlc activity under carefully controlled conditions. Third, neurophysiological and biochemical testing can shed light on the pathophysiology of altered muscle tone, sometimes predicting and often illuminating the effects of treatment. In clinical practice. the response of muscle tone to maintained passive stretch or to different drugs is helpful in supporting the clinical diagnosis. However. it is important to recognise that the relationship between tone and voluntary movement IS very complex, and that treatments that reduce muscle rigidity or spasticity can actually cause deterioration in voluntary function.
A TOPOGRAPHIC BRAIN MAPPING APPROACH TO THE STUDY OF ABNORMAL FACIAL MOVEMENTS.
M. Mkdici and L. Crispino
TREATMENT OF ANISMUS BY BIOFEEDBACK. (Hospital A. Mclnnes, (Western
General
Hospital,
Edinburgh,
UK)
Chronic constipation can be a result of anismus or unrelaxed pelvic floor muscles during defaecation. Such constipation can lead to many serious consequences. A measure of anismus using surface electrodes was devised comparing active squeeze with active straiting and found in 40% of patients with idiopathic constipation. These patients were treated with biofeedback using an auditory signal. Following this there was a subjective and objective response in 50-6058 of such patients indicating that this may be a learned response which can be rectified though further studies are required to see if this is maintained.
HOW TO DIFFERENTIATE TONE.
DISORDERS
OF MUSCLE
D. L. McLellan
(University
Italiano,
Montevideo,
Uruguay)
D. Peak, A. Smith and B. Ksimbie
of Southampton,
Southampton,
UK)
Disorders of muscle tone can be differentiated Clinical examination identifies the muscle groups
in 3 ways. involved, the
Topographic brain mapping recordings with backward averaging was performed on 10 patients. Five of them presented essential hemifacial spasm (HFS) and five abnormal facial movements described as tics. The use of backward averaging allowed the detection of a premotor wave associated with voluntary movements and recorded from premotor areas. This voluntary component may be either the only one responsible for the movement or may be related to synkinesis which takes place before, during or after the movement, whether a spasm or a tic. With such a tool we were able to separate abnormal movements into 2 categories: (1) movements associated with a premotor wave and therefore of cortical origin, and (2) movements without a premotor wave, orginating from subcortical structures. The advantages of this procedure lie in the accuracy of diagnosis. This becomes particularly important at the time of choice and initiation of treatment. In the case of HFS for instance, as described in another communication, when voluntary movements appeared as synkinesis, behavioral therapy such as biofeedback is suitable and in many cases movements described as tics have a cortical origin and therefore a voluntary component and behavior therapy or psychotherapy may be indicated. Thus, topographic brain mapping offers the possibility of detecting the true origin of abnormal movements and whether they have a cortical component or not.