Poster Abstracts Thursday, November 10, 2005 $465

MMG-PAP was measured in 16 patients with myopathies and compared to MMG-PAP of 16 non-myopathic disease controls and 25 normal individuals using the same procedure. Results: A positive direct correlation was found between force-PAP (mean: 197 ± 148%) and MMG-PAP (mean: 135 ± 68%) (p < 0.05). Mean MMG-PAP in myopathies (66 ± 53"/o) was significantly lower than disease (128 ± 34%; p < 0.005) and normal controls (120 ± 56 %; p < 0.005). Non-dystrophic myopathies, including those with myosifis, had much lower MMG-PAP values (38 ± 20?,'0; p < 0.005) than those with muscular dystrophy (148 ± 23°,5). Contusions: The M M G can be a useful index of muscle contractile force. [n addition, the low MMG-PAP observed in non-dystrophic myopathies may be helpful in differentiating this group from patients with muscular dystrophy and non-myopathic diseases.

1436 Electrophysiological evaluation of Carpal Tunnel Syndrome

Purl, V ], Singh, D 1, Nehru, R 1. 2Department of Neurology, G.B. Pant Hospital, New Delhi, India

50 hands, male 8 (1167,'o), female 42 (84%) with the diagnosis of carpal tunnel syndrome based on the diagnostic criteria of carpal tunnel syndrome of AAN (1993) were studied for distal motor latency and CMAP amplitude of median nerve and sensory median nerve latency as well as for comparative criteria between distal latency of median nerve of both sides, ulnar latency of same side, SNAP latency between sides of median nerve, and inching potentials. The mean age of the patients was 43.96 ± 10.28 (range 27 61) years. The symptoms in the descending order were: paraesthesia 74"/0; weakness 70"/0; aggravation of ssanptoms on sustained posture 70"/0, repetitive action 68°,5, sleep 44?,'0 and mitigated on change in posture 70?,'0, shaking of hand 26?,'0; sensory loss 16%. Phalen's sign was positive in 70?,'0 and 22% had atrophy of thenar muscles. 23 (92%) patients had bilateral involve- ment. Among the electrophysiological criteria the most sensitive was the comparative between the median and ulnar SNAP latency of the same hand (172"/o), followed by: inter latency difference between median and ulnar distal motor latency (50%), inching technique (148%) , comparison of median SNAP latency of both sides (140%), distal motor median nerve latency (38%) and inter median motor latency (126"/o) and distal median SNAP latency (26°,5). 18"/o of the hands although symptomatic were not meeting the electrophysiological criteria of carpal tunnel syndrome. Only two percent of the hands could be found on inching technique alone however, it was positive in another 48% of the hands. All of these hands exhibited one or the other electrophysiological criteria of carpal tunnel syndrome. Electro- physiological evaluation is important however, the comparative parameters correlate better than the inciting technique alone, in the diagnosis of carpal tunnel syndrome.

1438 Absolute and relative refractory periods in patients with Carpal Tunnel Syndrome

Saeed Talbrian ~, Gholam Reza Olyaei ~, Hossein Bagheir ~. ~Depart- merit of Electroneur@ysiology Research, Teheran University of Medical Sciences, Teheran, Iron

Introduction: Conduction of action potentials in neural system by sensory and motor fibers, provide possibility of comlection between different organs.

In electrophysiological assessments of tiffs system, attention to specific aspects will be useful for diagnosis. The purpose of this study is to evaluate the one of important physiologic principles of nerves, in patients with carpal tunnel syndrome (CTS). Method: Twenty-five patients with CTS participated in this study. Motor and sensory fibers of right and left median nerves stinlulated with paired stinlulation teChlffque. Compound nmscle action potential of abductor policies muscle and sensory nerve action potential of index

finger recorded and refractory periods of above fibers measured in mild and moderate CTS. Results: Patients with mild and moderate CTS in comparison to norntal range indicated increase of absolute and refractory periods of median nerves. There are no significant differences in absolute and relative refractory period of motor fibers between mild and moderate c r s , but in sensory fiber differences of refractory periods (absolute and relative) between mild and moderate CTS were significantly (P < 0.05). Comparison of refractory periods between right and left hand in above patients indicate no sigtffficant difference between them, but difference between sides with sever signs of CTS and other side just in sensory fibers indicate significant differences in absolute refractory period (P < 0.05).

The results o f this study determinate diagnostic value of sensory absolute refractory period, in primary stage of compression neuro- pathy such as CTS. In demyelination neuropattfies sensory relative refractory period can be useful for assessment.

1439 A study of cervical motor root conduction time in patients with Peripheral Neuropathies and Cervical Radiculopathies

Tamaru, T 1. 2 Kaikoukai Rehabilitation Hospital, Aichi, ,,rapan

To estimate conduction in the proximal motor root segment electrophysiologically, root conduction time (RCT) was defined as the time difference between M-wave latency by cervical magnetic stimulation (CMS) and the total peripheral conduction time calculated from the shortest F wave latency. In 60 patients with various neuro- logical diseases (Guillain-Barre syndrome (GBS): 8, inflannnatory demyelinating neuropatlffes (IDN): 6, diabetic polyl~europathy: 10, motor neuron disease: 12, cervical spondylosis: 15 and other neurological condifions:9), RCT was measured from unilateral median and ulnar nerves and compared to that from normal subjects. In patients with GBS and IDN, the prolongation of RCTs at median nerve and uhtar nerve were various and there was no certain tendency. However in patients with polyneuropathy, RCTs from both nerves were prolonged to the same extent. In patients with cervical spondylosis, PCTs were compared between pre- and post-surgical operation, and at the post-surgical condition RCTs were shorten in most case of whose symptoms were recovered after surgery. These findings suggest that the RCT might be a parameter for evaluating cervical motor root conduction.

1440 Nodal sodium currents in human Neuropathies and Motor Neuron Diseases

Tammca, N 1, Kuwabara, S ~, Misawa, S ~, Kanai, K 1, Ogawara, K ~, Nakata, M 1, Hattori, T 1. 2Department of Neurology, Chiba University School of Medicine, Chiba, Japan

Background and Objective: Sodium channels are over-expressed in the growing mxons after nerve injury. Approximately 1.0% of total sodium channels in manunalian axons are active at rest, termed a persistent sodium channel, and tiffs conductance can be estimated by the new electrophysiological techtffque of latent addition. To investigate changes in mxonal persistent sodium currents in human neuropathies and motor neuron diseases. Methods: Latent addition was performed in median motor axons of 35 normal subjects, 25 patients with axonal neuropathy, 15 with spinal muscular atrophy (SMA) and 25 with amyotrophic lateral sclerosis (ALS). Results: In normal subjects, persistent sodium channels increased with aging, presumably reflecting physiological motor neuronal loss and collateral sprouting by surviving motor neurons. Persistent sodium currents were sigtffficantly greater in the neuropathy, SMA, and ALS groups titan in age-matched normal controls. Ill neuro- pathy patients, sequential studies showed persistent sodium currents

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gradually increased as amplitudes of compound muscle action potential increased. Conclusions: Nodal persistent sodium currents commonly increase in patients with disorders affecting lower motor neurons, irrespective of causes. The increased axonal excitability could be responsible for positive motor symptoms such as muscle cramping frequently seen in these patients and normal elderly people.

1442 Relationship between biceps braclfii nmsde IIIlt.SS anti size of the evoked compound UluSde action potential

Wee, AS ~. 1University of Mississippi Medical Center, Yacicson, IvIississippi, USA

Background: Compound muscle action potential (CMAP) is the summat ion of the individual nmscle fiber action potentials produced during electrical nerve stimulation, and is a useful measure for assess- ing neuromuscular function. Objective: Determine if the size of the surface C M A P recorded from a large muscle such as the biceps brachii can be reliable in estimating the muscle mass. Methods: Supramaximal CMAPs were recorded from 32 normal biceps brachii muscles to stimulation of the musculocataneous nerve at the axilla. One-cm-diameter disc electrodes were used. Active electrode was at the middle of the muscle belly and reference at the tendon. Upper-arm circumference was measured with biceps muscle relm,~ed (elbow extended), and during contraction (full elbow flexion). Results: Mean C M AP duration - 16.45 ms, amplitude _ 10.50 mV, and area -- 96.13 mVms. Body mass index and absolute upper-arm circumference (biceps muscle relaxed or contracted) did not correlate with C M A P duration, amplitude, and area; Pearson correlation coefficients (r) ranged f r o m - 0 . 2 4 to 0.16. However, the difference (increment) in upper-arm circumference due to biceps muscle contrac- tion correlated with C M A P duration (r -- 0.47), amplitude (r -- 0.67), and area (r -- 0.75). Conclusions: C M A P size (amplitude and area) correlated well with biceps brachii muscle mass as estimated by the increase from baseline in upper-arm circumference during muscle contraction. The difference (increment) in upper-arm circumference due to muscle contraction reflects mainly the underlying biceps bractffi muscle bulk, and eliminates other variables such as thickness of subcutaneous tissues.

1443 Carpal Tunnel Syndrome: relationship between CMAPs recorded at the Thenar region from ulnar and median nerve stimulation

Wee, AS ~. Z University of Mississippi Medical Center, Yacicson, Mississippi, USA

Backgrouml: Thenar nmscles are primarily innervated by the median nerve. However, compound muscle action potentials (CMAPs) evoked by ulnar nerve stimulation can be recorded at the thenar region due to proximity o f some ulnar-innervated muscles, and from volume conduction events. Objective: Determine if loss of thenar muscle mass from carpal tunnel syndrome (CTS) could alter the size of ulnar C M APs obtained at the thenar region, because o f changes in the physical surroundings and electrical conductivity. Methods: Supramaximal CMAPs were recorded from the thenar area to electrical st imulation of the ulnar nerve at the wrist and median nerve at the pa lm in 95 hands with CTS. Needle E M G was done in the thenar muscles. Median/ulnar C M A P amplitude ratios were calculated. Results: Needle E M G severity was negatively correlated with median- C M A P amplitude (r - -0.72), but not with u lnar -CMAP amplitude (r - 0.15). There was no correlation between median and ulnar C M A P amplitudes ( 0.18). E M G severity had modest negative correlation (r -- 0.37) with median/ulnar C M A P amplitude ratios.

Mean median/ulnar C M A P amplitude ratios for normal E M G and mild, moderate, and severe E M G abnormalities were 3.72, 3.32, 1.71, and 0.45, respectively. Conclusions: The absolute amplitude of the ulnar C M A P recorded at the thenar region does not seem to be influenced by changes in the physical envirormlent due to thenar muscle loss (atrophy) from median nerve pathology. The median/ulnar C.MAP amplitude ratio is usually > 1.0; if it falls below 0.5, the s tudy suggests severe loss of motor units

in the thenar muscles.

1444 Peduncular Hallucinosis and dreams: a common source?

Feve, A ~, Hart, G ~. 1Service de Neurologie, Hopital Leopold Bellan, Paris, France

Headings: to discuss the psychological and physiological nature of peduncular hallucinosis in relation relation with dreams. Background: Peduncular hallucinosis is a pathological form of onirism which occurs as a result of a cerebrovascular accident located in the cerebral peduncle. There is few literature about its significance and pathophysiology. Method: We will discuss the case of a patient who experienced tiffs hallucinosis characterised by a rich orfirism and the recurrence of the hallunation theme in her dream after the neurological episode. Result: The hallucination was: She saw herself t ransported alive in a coffin carried by a m a n in a boat. She also presented a diplopia, and the diagnosis was oriented to a neurological pathology rather than a psychiatric one. The cerebral MRI scan revealed a right cerebral peduncular infarction.

Six months later she had fully recovered neurologically but had a lot of nocturnal dreams and diurnal anxiety about them. She was then asked to report her dream and her impression. Thus , she reported multiple dreams with a content resembling her hallucinosis. The Contents of the dreams were about a sentiment to be abandoned and carried from one place to another, to be lost, to be in a room where unknown people come. The nature of her dreams progressively broadened to more familiar subject matter and, by contrast with the stroke episode, she was thus able to differentiate between what she had hallucinated and the reality.

Discussion Peduncular hallucinosis is commonly associated with an altered state of consciousness, emotional disturbance and anxiety. Links between neurological pathology and dreams occurring after the stroke will be discussed. The involvement of brain stem centers of REM sleep and their relation with the mechanisms of dream and ponrine pseudo-hallucinations could be discussed.

1445 Efl~ct of alcohol on initiation anti tnaintenance of sleep

Ghanem, Q1. 1 University Of Ottawa, Canada

The use of alcohol is universal. It is often not considered to be a drug by the patient, and its effect on sleep is generally underestimated. Patients often minimize their alcohol consmnption. These factors need to be considered by physicians when they assess insomrfia, obstructive sleep apnea and other sleep disorders. The effect of alcohol on initiation and maintenance of sleep and on sleep architecture will be discussed, and suggestion for management offered.

1446 Dopaininergic therapy of dlfldhood-onset Restless Legs Nym[route

Kotagal, S 1. ~Division of Child and Adoleseent Neurology and the Sleep Disorders Center, Mayo Clinic, Rochester, Minnesota, USA

Background: There is little available information about the treatment of childhood restless legs s~ldrome (RLS). The objective of tiffs s tudy was to detet~dne the efficacy of pramipexole, a dopanffne agonist, in treating this disorder.