ABSTRACT
Previous research on tremor pathophysiology showed that tremor can be affected, e.g. by electrical stimulation of the peripheral nerve, mechanical perturbation of the limb and by transcranial magnetic stimulation of the motor cortex. This report is focused on possible effects of muscle vibration (MV) on resting tremor in Parkinson's Disease (PD). Vibratory stimulation was applied to the tendons of M. extensor carpi radialis longus and M. flexor ulnaris in 27 subjects with moderate PD resting tremor. The following effects were observed: (1) tremor stopped or started time-locked to MV onset and offset, (2) tremor persisted during MV but its frequency pattern changed. These results are discussed with specific emphasis to effects of MV on spinal and supraspinal levels.
Subject(s)
Parkinsonian Disorders/physiopathology , Proprioception/physiology , Tremor/physiopathology , Vibration , Aged , Aged, 80 and over , Electromyography , Female , Forearm/physiopathology , Humans , Male , Middle Aged , Tendons/physiopathology , Time FactorsABSTRACT
Tonic vibratory stimuli of 1000 ms duration and different frequencies were delivered to muscles of the forearms of young human subjects. Evoked potentials (EPs) were recorded from 29 scalp channels and revealed phasic highly lateralised and focally distributed EPs during the first 100 ms of the recording epoch that could be adequately modelled with a single point dipole source located in the vicinity of the central sulcus contralateral to the stimulated arm. A later negativity with an onset of about 400 ms and a duration of about 800 ms was found to be symmetrically distributed over fronto-central regions. This negativity is interpreted in terms of cortical activation beyond the primary sensory fields and could be related to the kinaesthetic phenomena experienced during muscle vibration.
Subject(s)
Cerebral Cortex/physiology , Evoked Potentials/physiology , Muscle, Skeletal/physiology , Vibration , Adult , Afferent Pathways , Female , Humans , Physical StimulationABSTRACT
A young obese woman with menstrual irregularities presented with bilateral papilledema, abducens nerve paresis, visual obscurations and severe headache. Neuroimaging studies were normal but CSF opening pressure was elevated. The diagnosis of idiopathic intracranial hypertension was made. Insertion of a shunt quickly alleviated the symptoms. A few weeks later the patient developed a left femoral nerve paresis and an ulnar nerve paresis on the right. Electrodiagnostic tests confirmed the diagnosis of mononeuropathia multiplex. Bone marrow histology showed a vasculitis. We hypothesize that the vasculitis is underlying both, idiopathic intracranial hypertension and mononeuropathia multiplex.
