Propriospinal Myoclonus: Clinical and Neurophysiologic Characteristics

BACKGROUND: Propriospinal myoclonus (PSM) is characterized by rhythmic or arrhythmic, flexion or extension movements of the axial body muscles involving many spinal segments linked by long propriospinal pathways. We described the clinical and electrophysiological features of 7 PSM patients. METHODS: Neurophysiologic studies included routine electroencephalography, polymyography, and posterior tibial somatosensory evoked potentials (PTSEP). RESULTS: Myoclonic jerks originated from the rectus abdominis in 3 patients, and pectoralis major, thoracic paraspinalis, sternocleidomastoid, and vastus lateralis in every other case. Polymyography showed rostral and caudal propagations from the originated muscles. The durations of myoclonic jerks were about 100 to 400 ms and their velocities ranged from 3.2 to 6.7 (5.4+/-1.4) m/s. PSM developed after cervical trauma in 2 patients (cases 1, 2), after general anesthesia in case 4, and after infectious or inflammatory myelopathy in case 3. PSM in 3 patients were idiopathic, of which one patient had diabetes mellitus for 10 years with autonomic and somatosensory polyneuropathy. Two patients, who showed PSM after general anesthesia and myelopathy respectively, were cured completely within one month. Though others had not completely recovered, they had a relatively benign course. CONCLUSIONS: In our cases, the generators of myoclonus seemed to be most commonly located in the midthoracic lesion of the spinal cord with up and down propagation of slowly conducting pathways, such as propriospinal fibers. Cervical trauma can lead to the partial release of a spinal pattern generator, which is capable of recruiting muscles through long propriospinal pathways into complex rhythmic activity.

Clinical Characteristics of the Subtypes of Guillain-Barre Syndrome according to the Electrodiagnositic Criteria

BACKGROUND: Guillain-Barre syndrome (GBS) is defined as a recognizable clinical entity that is characterized by rapidly evolving symmetric limb weakness, loss of tendon reflexes, absent or mild sensory signs, and variable autonomic dysfunctions. Recently, GBS has been classified as a classical demyelinating (acute imflammatory demyelinating polyradiculoneuropathy, AIDP) and two axonal (acute motor axonal neuropathy, AMAN, and acute motor sensory axonal neuropathy, AMSAN) forms. The clinical pattern and prognosis according to type is not clear. METHODS: Forty-one patients clinically diagnosed as GBS were enrolled and classified as AIDP, AMAN, and AMSAN according to electrodiagnostic criteria. We analyzed the clinical data of each subgroup; age, sex, seasonal distribution, history of previous illness, cranial nerve involvement, respiratory involvement, and motor weakness. RESULTS: Forty-one patients with GBS were comprised of 19 patients (46.3%) with AIDP, 12 patients (29.2%) with AMAN, and 10 patients (24.3%) with AMSAN. AIDP was found more frequently in males and in winter (42.1%) while axonal forms of GBS showed neither gender nor seasonal predominance. Frequency of cranial nerve involvement was not different between the sub-groups of GBS, whereas respiratory involvement was more frequent in AMSAN (50%). Upper limbs were weaker in axonal than in demyelinating types of GBS. CONCLUSIONS: Axonal forms of GBS showed some clinical characteristics distinctive from the demyelinating forms, which might be useful in the differential diagnosis of subgroups of GBS. (J Korean Neurol Assoc 19(5):503~508, 2001)

A Case of Intramedullary Myelopathy Associated with Small Cell Lung Cancer

Subacute paraneoplastic myelopathy is a rare cause of myelopathy. Serepositivity for antineuronal nuclear antibodies-1(ANNA-1, Anti-Hu) is a sensitive and specific marker for the paraneoplastic syndrome with small cell lung cancer. A 57-year-old male patient was admitted because of acutely progressive paraparesis, anesthesia of both lower limbs and loss of bladder function over 3 days. He was subsequently found to have small cell lung carcinoma of limited stage. Magnetic resonance image of the thoracic spine showed signal abnormalities with mild focal enhancement in the intramedullary portion of C7-T10 segments. Concurrent CSF cytology showed no abnormal findings. He had high sero-logic titer of ANNA-1. These findings suggest of a paraneoplastic syndrome although we didn't have nectrotic patholog-ic findings. Five months after onset of neurological symptoms, he died inspite of chemotherapy and radiotherapy. We report a case of intramedullary myelopathy, probably of paraneoplastic origin, associated with small cell lung cancer.

Nerve Conduction Study of Electrophysiologically Defined Severe Carpal Tunnel Syndrome Before and After Surgical Release

BACKGROUND: A nerve conduction study (NCS) is a useful method to diagnose and evaluate the therapeutic effect of carpal tunnel syndrome (CTS). Severe CTS often shows evidence of axonal injury, which may lead to incomplete recovery of symptoms or NCS abnormalities. To evaluate the degree of NCS recovery after decompression in patients with severe CTS, we studied NCS before and after surgical release in severe CTS with electrophysiological evidence of axonal injury. METHODS: We analyzed the NCS changes in 17 patients (21 hands) with severe CTS just before and 1 year after CTS release. The severe CTS was electrophysiologically defined with the following criteria; 1) prolonged median sensory and motor distal latencies, 2) either an absent SNAP or low amplitude/absent thenar CMAP, and 3) abnormal needle EMG findings. The patients averaged 53.3 years of age and all were females. RESULTS: The mean interval between the first and second NCS was 20.5 months and post-operation symptoms were free in 8 hands, markedly (>50%) improved in 11 hands, and symptoms remained (< 50%) in 2 hands. In 13 hands, SNAPs were not elicitable before surgery, but all were obtainable after surgery. One patient who had no CMAP did not show recovery after surgery. The mean median sensory latency, SNAP amplitude, and sensory NCV over the finger-wrist segment improved significantly (P < 0.05). The mean median motor latency and CMAP amplitude also improved significantly (P < 0.05). The parameters of NCS, however, showed incomplete and subnormal recovery after decompression except for sensory latency, amplitudes of SNAP and CMAP which recovered to the normal range. CONCLUSIONS: After CTS release even with electrophysiologically defined severe CTS patients, there were significant improvements of clinical symptoms and electrophysiological parameters. However, only some parameters(median sensory latency, SNAP amplitude and CMAP amplitude) were restored to the normal range.

Myotonic Dystrophy in Pregnancy complicated with Preterm Labor and Congestive Heart Failure / 대한산부인과학회잡지

Myotonic dystrophy is an autosomal-dominantly inherited neuromuscular disorder characterized by slowly progressive muscular dystrophy, muscle weakness and myotonia. The clinical features may vary from just cataracts to involvement of multiple organ systems such as various muscles, heart, lung and intestine. During pregnancy and delivery, serious maternal and obstetrical complications may occur. The myotonia is often aggravated during pregnancy and it leads to obstetrical complications such as fetal loss, preterm premature delivery, hydrops, in-utero fetal death, difficulties in fetal expulsion, postpartum hemorrhage and/or anesthetic accidents. The affected neonate may display severe hypotonia, facial displegia and respiratory distress. This report presents a woman with myotonic dystrophy complicated with congestive heart failure and preterm delivery during pregnancy.

The accessory deep peroneal nerve : frequency and electrophysiological findings

The accessory deep peroneal(ADP) nerve is known as a common anatomical variant. It may alter the usual clinical and electrophysiological charateristics of peroneal nerve lesions. The purpose of the study was to investigate the frequency of occurrence and the electrophysiologic characteristics of the ADP nerve. We performed peroneal motor nerve conduction studies in 434 patiets with conventional method. When the CMAP amplitudes evoked by distal peroneal stimulation is smaller than that by proximal stimulation, we searched ADP nerve by stimulation at posterior to the lateral malleolus. In 60 patients, we searched ADP nerve regardless of CMAP amplitude difference. Additionally, we routinely stimulated the region of posterior to the lateral malleolus with recording at the medial and lateral extensor digitorum brevis(EDB) muscles using multi channel EMG in 34 patients. In conventional peroneal nerve conduction study, ADP nerves were detected in 27(8.2%) patients out of 330 studied patients(right 7, left 15, both 5). Mean amplitue of ADP nerve was 1. 52mV (right 1. 90, left 1. 84). In routine ADP stimulation study, ADP nerve was detected in 5(21.7%) out of 23 patients(left 2, both 3). In 4 of them, the distal peroneal amplitudes were greater than the proximal. Mean amplitude was 1.86mV(right 1.38, left 1.65). In conclusion, we confirmed that the accessary deep peroneal nerve is a relatively common variant and its presence may not be predicted by the difference of amplitudes between the distal and proximal peroneal segments in conventional peroneal nerve conduction study. So in cases of suspected peroneal nerve lesions, ADP nerve should be searched.

Relapsing sensory ataxia initially manifested by miller-fisher syndrome

We experienced a patient who manifested Miller-Fisher syndrome initially, and progressed relapsing ataxia later, There was electrophysiologic evidence of distal sensory polyneuropathy with completely sparig of somatic motor nerves. Sural nerve biopsy showed severe segmental demyelination. All the symptoms improved by intravenous immunoglobulin dramatically but after a period of remission, progressive ataxia reappeared. Plama exchange had some effect and prednisolone alone showed no definite improvement. High dose of prednisolone combined with IVIgG made remission for a long time. We believe that this patient had an unusual form of inflammatory polyneuropathy, a relapsing variant of the Miller-Fisher syndrome of acute idiopathic polyneuritis. In this case, IVIgG was the most effective therapy and prednisolone was added as a long term therapy successfully.