Clinical, Neurophysiological and Morphological Findings in Eaton Lambert Syndrome

Abstract

Two patients with maysthenic syndrome apparently not associated with carcinoma were studied in detail with repetitive stimulation of motor nerves, single fibre eleetromyography and histology. One patient showed signs of widespread autonomic dysfunction and the other patient had from the presynaptic terminals, usually produces a good relief of the symptoms (Karnenskaya e f al. 1975 a, b, Elmqvisf & Larnberf 1968).We recently had the opportunity to study in some detail two cases of myasthenic syndrome apparently not associated with carcinoma. Both cases fulfilled clinical and electrophysiological criteria of the disorder.CASE REPORTS Case f. A 64-year-old woman with a history of right-sided kidney stones but otherwise previously healthy. Since March 1972 she had experienced multifocal CNS symptoms including a constant disabling tiredness and suddenly developing attacks resembling multifocal epileptic seizures. During the attacks lasting for a few minutes she had tonic and clonic muscle contractions in different sides of the body at different attacks. Consciousness was retained but the ability to speak was lost.Once such an attack proceeded into a grand ma1 seizure. From March 1972 a slowly progressing dysarthria and a weakness of proximal leg muscles were noted. The latter symptoms showed spontaneous day-to-day fluctuations. At the beginning of 1975 she could only walk short distances and often fell in her home. At that time she started to use a wheelchair and the dysarthria was very pronounced.At the first admittance to the ward in November 1972, neurological examination revealcd only a moderate dysarthria, a weakness of proximal limb muscles most pronounced in the legs, and a lack of the ankle jerks whereas the other muscle reflexes were weak. Hemogram and laboratory tests of serum including protein electrophoresis, electrolytes, creatinine, alcaline phosphatases, y-glutamic transferase, aspartate-amino transferase, alaninc-amino transferase, creatine phosphokinase, fasting blood glucose, and VDRL-Meinicke were all normal. Routine tests of urine and tests for porphyria (porphobilinogen and A-amino levolinic acid in urine) were negative. CSF examination for cells, protein concentration, electrophoretic protein pattern, and hemoglobin extinction was also normal. Neurootological examinations performed by Dr. N. G. Henriksson (Neuro-otological Department, University Hospital, Lund) on five occasions during the disease (before and during guanidine treatment, see below) showed a persistent and pronounced impairment of the fast component of the vestibular and optokinetic nystagmus. The pursuit eye movements showed a varying degree of disturbance, while no clear-cut abnormality was found in the voluntary saccades. The findings were interpreted as a general disturbance of the fast phase system in the parapontine gaze centre. Repeated electroencephalography and isotope encephalography examinations were normal. Pneumoencephalography failed on two occasions in 1973 as no air passed intraventricularly. Selective angiography o...

Shape Variability of Potentials Recorded by a Single-Fiber Electrode and its Effect on Jitter Estimation

“…5), it is clear that the RTV may not have great importance in myasthenic or LEMS patients who typically have pronounced clinical manifestations and a lot of jitter values well above the upper limits. 11,21,22,25 However, when the jitter is increased only slightly, as in mild clinical manifestations of myasthenia gravis, early stages of reinnervation, 9 myopathies, and Duchene dystrophies, 24 even one more abnormal jitter value may be important for the diagnosis. From the foregoing we conclude that, because of the RTV effect, special care should be taken in the interpretation of jitter results obtained from muscles with low reference jitter values of patients suffering from disorders that moderately affect the end-plate transmission.…”

“…5d and 5h, we could say that the effect of RTV would be negligible when the neuromuscular jitter is higher than 70-80 ls. This means that the IPI fluctuations produced by an abnormally large variability of the end-plate transmission, as in Lambert Eaton myasthenic syndrome (LEMS) disorders, 11,22 would obscure almost completely the IPI fluctuations due to the RTV.…”

The stretch reflex in the Eaton Lambert syndrome, myasthenia gravis and myotonic dystrophy

“…In myasthenia gravis they are usually not significantly changed but may be decreased by muscle work. This was confirmed in two patients with the myasthenic syndrome in whom a carcinoma could not be demonstrated (Henriksson et al 1977). In the myasthenic syndrome, however, the muscle stretch reflexes are usually affected, particularly in the lower limbs (Lambert h Rooke 1965, Henson 1974.…”

“…In the myasthenic syndrome, however, the muscle stretch reflexes are usually affected, particularly in the lower limbs (Lambert h Rooke 1965, Henson 1974. A 65-year-old woman with myasthenic syndrome not associated with carcinoma since March 1972 (case 1 in Henriksson et al 1977). This was confirmed in two patients with the myasthenic syndrome in whom a carcinoma could not be demonstrated (Henriksson et al 1977).…”

“…A 64-year-olld woman with myasthenic syndrome with n o demonstrable associated carcinoma since October 1975 with marked fluctuations of the condition (case 2 in Henriksson et al 1977). A 64-year-olld woman with myasthenic syndrome with n o demonstrable associated carcinoma since October 1975 with marked fluctuations of the condition (case 2 in Henriksson et al 1977).…”