1/72. Cardiac involvement in proximal myotonic myopathy. Proximal myotonic myopathy (PROMM) is a recently described autosomal dominantly inherited disorder resulting in proximal muscles weakness, myotonia, and cataracts. A few patients with cardiac involvement (sinus bradycardia, supraventricular bigeminy, conduction abnormalities) have been reported. The cases of three relatives with PROMM (weakness of neck flexors and proximal extremity muscles, calf hypertrophy, myotonia, cataracts) are reported: a 54 year old man, his 73 year old mother, and 66 year old aunt. All three presented with conduction abnormalities and one had repeated, life threatening, sustained monomorphic ventricular tachycardia. This illustrates that severe cardiac involvement may occur in PROMM. ( info) |
| A 37-year-old man with sarcoidosis developed severe electrical and clinical myotonia while taking pravastatin for hypercholesterolemia. myotonia associated with sarcoidosis is rare. pravastatin is associated with myotonia in animals. This case suggests that sarcoidosis and pravastatin, two entities not frequently associated with myotonia, may interact in a synergistic manner to produce severe clinical myotonia in humans. ( info) |
3/72. A case of ocular neuromyotonia with tonic pupil. A 48-year old woman with hypertension experienced painful oculomotor nerve palsy. After surgery for a giant aneurysm of the internal carotid artery in the cavernous sinus, phasic constrictions of the pupil developed. Two years later, this phenomenon disappeared and was replaced by intermittent involuntary cyclic spasms elevating the ptosed lid. These cyclic lid movements were not elicited with any eye movement or by increased accommodation. The pupil now manifested the pharmacologic features of a tonic pupil. The explanation for this unique case of ocular neuromyotonia is based on a misdirection phenomenon, possibly caused by ephaptic transmission. ( info) |
| The clinical signs of the rarely encountered ocular neuromyotonia consist of transient involuntary tonic contraction and delayed relaxation of single or multiple extraocular muscles, resulting in episodic diplopia. With a mean time delay of 3.5 years, this motility disorder frequently follows tumor excision or adjuvant radiation near the skull base. Ocular neuromyotonia may reflect inappropriate discharge from oculomotor neurons with unstable cell membranes because of segmental demyelinization by tumor compression and radiation-induced microangiopathy. In the present paper, the authors present the case of a 53-year-old patient with a history of transsphenoidal hypophysectomy and adjuvant radiotherapy, who underwent strabismus surgery for abducens palsy. ( info) |
5/72. Neuromyotonia, myocloni, sensory neuropathy and cerebellar symptoms in a patient with antibodies to neuronal nucleoproteins (anti-Hu-antibodies). A middle-aged patient presented with subacute muscular stiffness, myocloni of both extremity and facial muscles, gait ataxia and symmetrical distal painful paraesthesias. Electrophysiologically, neuromyotonia was confirmed. High titer anti-Hu antibodies were detected, but no other paraneoplastic antibodies were found. Small-cell lung cancer was diagnosed. Under chemotherapy tumor remission was achieved and, except for minor sensory deficits, neurological symptoms disappeared. This report shows that paraneoplastic syndromes associated with antibodies to neuronal nucleoproteins (anti-Hu antibodies) may be associated with a syndrome including neuromyotonia, sensory neuropathy, cerebellar symptoms and myocloni. ( info) |
| The authors report a Japanese family with dominantly inherited heat-induced myotonia and cold-induced paralysis with hypokalemia. This phenotype is associated with a novel mutation in the voltage-dependent skeletal muscle sodium channel alpha subunit (SCN4A). This Pro1158Ser mutation is localized between the fourth and fifth transmembrane segments of domain III in SCN4A and may give rise to a new function; that is, thermosensitive permeability changes of the sodium channel. ( info) |
7/72. hypothyroidism with subacute pseudomyotonia--an early form of Hoffmann's syndrome? Report of a case. A 25-year-old man was admitted to the hospital because of painful muscle cramps and action myospams of subacute onset and 6 weeks' duration. No myotonia could be demonstrated objectively and his deep tendon reflexes showed no prolongation of the relaxation phase. serum creatinine was raised but creatinine clearance was normal. serum levels of aldose, CPK, ASAT and ALAT were increased but ordinary light microscopy revealed no histological signs of muscle disease in a quadriceps biopsy. ECG showed a prolonged PQ interval and flat T waves in the left precordial leads. Laboratory tests of thyroid function revealed intensive hypothyroidism, and high titers of circulating thyroid antibodies were demonstrated. During 2 1/2 months of thyroid therapy, the muscle symptoms gradually disappeared completely and the patient could return to work. By that time the serum enzymes and the ECG had normalized. Despite the lack of objective signs of myotonia, we consider that the very dominant subjective muscle symptoms, severe enough to prevent the patient from performing his ordinary manual work and completely reversible on thyroid therapy, justify the designation of hypothyroid myopathy. The question is raised whether the case represents an early form of Hoffmann's syndrome. ( info) |
8/72. myotonia and keratoderma induced by 20,25 diazacholestenol. A new inhibitor of cholesterol synthesis, 20,25 diazachlestenol, produced myotonia in 31 persons; and, in six of these, a keratoderma which resembles the natural disease, keratoderma climactericum. These observations further emphasize the importance of normal lipid synthesis in orderly cornification. ( info) |
9/72. Myotubular myopathy associated with cataract and electrical myotonia. A case of myotubular myopathy is described which is unusual because of bilateral cataracts and prominent myotonic-like discharges on the EMG. The significance of these findings is discussed in relation to dystrophia myotonica. ( info) |
10/72. Laryngeal spasm complicating pseudomyotonia. Pseudomyotonia is a syndrome characterized by progressive muscle stiffness, weakness, myokymia, hyperhydrosis, and wasting of muscle. It especially affects the distal aspect of the extremities. The electromyogram is characteristic, and shows continuous muscle activity at rest. We discuss a case that is believed to be the first recorded instance of pseudomyotonia complicated by airway obstruction secondary to laryngeal spasm. Treatment with phenytoin sodium resulted in rapid improvement of the peripheral symptoms and simultaneous resolution of the laryngeal spasm. ( info) |