Resting tremor

Antagonists of muscarinic acetylcholine receptors had widely been used since 1860 for the treatment of Parkinson s disease, prior to the discovery of l-DOPA. They block receptors that mediate the response to striatal cholinergic interneurons. The antiparkinsonian effects of drugs like benzatropine, trihexyphenidyl and biper-iden are moderate the resting tremor may sometimes respond in a favorable manner. The adverse effects, e.g., constipation, urinary retention, and mental confusion, may be troublesome, especially in the elderly. 

Resting tremor is a tremor present at rest, which usually abates during voluntary movements. Its frequency in Parkinsonism is 4-8 Hz and it occurs most often in the distal extremities. 

Disorders of the human cerebellum result in three types of abnormalities. The first is hypotonia or reduced muscle tone. Another includes abnormalities in the execution of voluntary movements or ataxia (defective muscular coordination). The third type of muscular malfunction is intention tremors. These tremors differ from the resting tremors of Parkinson s disease in that they occur during a movement and are most pronounced at the end of the movement when the patient attempts to terminate it. 

For clinically probable PD, the patient exhibits at least two of the following resting tremor, rigidity, or bradykinesia. Asymmetric onset (unilaterality) of these features is usual. 

In this case, a more careful psychiatric and physical examination can be of help. Although there are admitted similarities to depression and the negative symptoms of schizophrenia, Parkinson s disease is also associated with a resting tremor, called cogwheel rigidity, and at times drooling. These other symptoms are not typically due to psychiatric illness. If these symptoms are present, one should investigate the possibility of a medication side effect or the presence of Parkinson s disease. 

Relief of symptoms, such as an improvement of masklike facial expression, muscular rigidity, shuffling gait, and resting tremors of the hands and head... 

A fine resting tremor is a common side effect. P-Adrenergic-blocking drugs, such as propranolol (<80 mg/day in divided doses), are effective in treating this tremor. Subjective memory impairment commonly occurs and is among the most frequent reasons for noncomphance (Goodwin and Jamison 1990). 

Parkinson disease or parkinsonism The clinical syndrome of bradykinesia, rigidity, resting tremor, and postural instability associated with neurotransmitter abnormalities within the basal ganglia. 

Parkinsonism is a clinical syndrome that comprises four main features bradykinesia (a slowness and poverty of movement), muscular rigidity (increased resistance of muscles to passive movement), resting tremor, which usually disappears during voluntary movement, and abnormalities in posture and gait. 

Gross C., Guehl D. Effect of deep brain stimulation on amplitude and frequency characteristics of rest tremor in Parkinson s disease. Thalamus Relat Syst, 2001,... 

Although replacement therapy is classically exemplified by the treatment of hypofunctioning endocrine glands, there is an important neurological disorder that can be successfully treated with a replacement strategy. Parkinson s disease is a clinical syndrome characterized by slowness of movement, muscular rigidity, resting tremor, and an impairment of postural balance. In the absence of therapy, death frequently results from complications of immobility. 

Once a stable chronic model has been established,the affected primates exhibit a typical Parkinsonian syndrome, for which a variety of behavioral measures have been developed. These include neurological descriptions of symptoms typical of human PD including action and resting tremor, cogwheel rigidity, postural impairments, hypokinesia and... 

Emborg ME, Tetrud JW, Moirano J, McLaughlin WW, Bankiewicz KS (2003) Rest tremor in rhesus monkeys with MPTP-induced parkinsonism. Front Biosci 3 48-54. 

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