BRITISH MEDICAL JOURNAL VOLUME 293 9 AUGUST 1986 379 Br Med J (Clin Res Ed): first published as 10.1136/bmj.293.6543.379 on 9 August 1986. Downloaded from Clinical Algorithm Parkinson's disease N P QUINN, F A HUSAIN Idiopathic Parkinson's disease is a degenerative neurological dis- importance of oculogyric crises occurring in a patient with Parkinson's order classically presenting in old or late middle age. The brain disease receiving dopaminergic treatment is unknown. shows characteristic cell loss and depigmentation in pigmented Huntington's disease-Most patients with akinetic-rigid Huntington's disease are young (onset before age 20), 90% inheriting their "Westphal brain stem nuclei. The presence of rounded eosinophilic intra- variant" from an affected father. Additional dystonic features are common cytoplasmic inclusions, known as Lewy bodies, in some of the and mental changes profound. Older subjects with Huntington's disease neurons qua non affected is a sine for definitive pathological rarely present with an akinetic-rigid syndrome, but in many adult patients diagnosis. In life, however, the diagnosis of idiopathic Parkinson's parkinsonian features develop as the disease progresses, even without disease rests entirely on clinical features and is primarily one of neuroleptic treatment.3 The family history and the mental changes point exclusion. towards the diagnosis. A paucity of a rhythm on the electroencephalogram and caudate atrophy on computed tomography may provide additional clues. A gene specific test on DNA harvested from whole blood may become available. Parkinsonism Wilson's disease-Young subjects with parkinsonism (onset before age 40) should have blood and urine tests of copper metabolism and slit lamp The first prerequisite is the recognition of parkinsonism, which comprises examination for Kayser-Fleischer rings. Traditional teaching holds that two or more of the following signs: tremor, rigidity, akinesia, and postural neurological Wilson's disease never begins after the age of 40, is never abnormality (either flexed posture or impaired postural reflexes). From then diagnosed after the age of 50, and is always associated with Kayser-Fleischer onwards unusual clinical features, with or without the results of ancillary rings. Despite two recently reported, and hotly debated, possible exceptions investigations, may point to alternative causes of the syndrome. Many of to these rules,4 for practical purposes Kayser-Fleischer rings are always these atypical features may be evident only with time, so that a clinical found in neurological Wilson's disease (but not hepatic Wilson's disease' so diagnosis ofidiopathic Parkinson's disease must be continually re-evaluated. long as slit lamp examination is performed by an experienced ophthalmolo- Progress down the algorithm therefore resembles an upside down version of gist. Other family members may be affected, and a history of parental snakes and ladders: the appearance of an unusual feature at any time in the consanguinity may be elicited. course of the disease may call for the whole case of differential diagnosis to be is common and, like idiopathic Parkinson's reopened. Here we briefly consider the important features of the different Drug induced parkinsonism disease, the incidence increases with age. It can result from treatment with diagnostic possibilities in the boxes across the middle of the algorithm in a any receptor drug of the phenothiazine, more conventional manner. This background information provides the neuroleptic (dopamine blocking) rationale underlying the algorithm. butyrophenone, thioxanthene, or benzamide class and also from treatment http://www.bmj.com/ Benign essential tremor-This monosymptomatic disorder, dominantly with dopamine depleting agents such as reserpine and tetrabenazine. overlooked are metoclopramide (Maxolon), inherited but with variable penetrance, is commoner than Parkinson's Causative drugs commonly (Stemetil), and various antidepressant-anxiolytic-neuro- disease and shows a similar rising prevalence with increasing age. It is often prochlorperazine temporarily relieved by alcohol, improved by blockers, and exacerbated by leptic combinations, such as Motival. It is also surprising how often a history of depot injections is not picked up. If the condition is due to drugs alone Pl agonist drugs. It is probably the most frequent cause of misdiagnosis. Although cogwheeling of affected limbs due to the tremor is allowable, such patients usually recover after six months without medication, although months to two years may occasionally be necessary. When parkinsonism classical rigidity, akinesia, and other parkinsonian features are lacking. 18 period the patient may have been destined to develop Some patients with idiopathic Parkinson's disease may display a fast postural persists after this anyway. Several patients whose first parkin- on 26 September 2021 by guest. Protected copyright. tremor as well as, or sometimes instead of, a classic slow resting tremor. idiopathic Parkinson's disease symptom is a vague complaint of unsteadiness or "dizziness" may in Also, many patients with akinetic-rigid parkinsonism may never develop sonian tremor. fact be given prochlorperazine, thus hastening the appearance of other Postencephalitic Parkinson's disease-Enecephalitis lethargica is the only features of the disease. The reason some patients treated with antidopa- whereas others ofthe same age treated frequently accepted encephalitic cause of persisting Parkinson's disease.' minergic drugs develop parkinsonism same do not unknown but may well be related to the extent Cases are extremely rare. Although the typical patient gives a history of with the doses is encephalitis and oculogyric crises followed by the development of parkin- oftheir basal gangliar "dopamine reserve" (in idiopathic Parkinson's disease reserve Those with sonism at a relatively young age, diagnosis is confounded on the one hand by 80% of dopamine is lost before clinical signs appear). may at increased risk of developing the fact that patients without a preceding history of oculogyric crises or drug induced parkinsonism be evidence for this is encephalitis have been described (one of the latter showing at necropsy the idiopathic Parkinson's disease later, but epidemiological classical sequelae ofencephalitis lethargica2) and on the other by the fact that lacking. recently many papers referred several patients with the changes ofidiopathic Parkinson's disease may give a Arteriosclerotic pseudoparkinsonismn-Until to as an Now, history of some unrelated encephalitic illness. Persisting signs ofpupillary or arteriosclerotic Parkinson's disease aetiological subgroup. to no part Parkinson's oculomotor disturbance or of associated dystonia and extremely slow however, cerebrovascular disease is recognised play in now progression of the disease may be useful clinical clues. The diagnostic disease and the condition is dubbed arteriosclerotic pseudoparkin- sonism. Most patients display neither classical rest tremor nor true akinesia and usually walk with an erect "military," albeit shuffling, gait (the term "marche a petit pas" was originally coined for these subjects). Those affected are most often elderly and hypertensive and may have other vascular risk factors, suffer additional dementia, and show lacunar infarcts in basal ganglia, larger multiple infarcts elsewhere, or extensive symmetrical white College School of Medicine and Dentistry, London SE5 9RS King's matter lucency ("Binswanger change") on computed tomography. Matters N P QUINN, MB, MRCP, lecturer in neurology are complicated by the fact that the infarcts may be too small to be F A HUSAIN, medical student demonstrable on computed tomography and also that idiopathic Parkinson's Correspondence to: Dr Quinn. disease and lacunar infarction are often associated since both conditions are common among the elderly. Only in the minority with coincidental 380 380 ~~~~~~~~~~~~~~BRITISHMEDICAL JOURNAL VOLUME 293 9 AUGUST 1986 Br Med J (Clin Res Ed): first published as 10.1136/bmj.293.6543.379 on 9 August 1986. Downloaded from ;., :-,. .,. '. .. -1 .. I Potralt-anorrity Akitn '?. " , I U-' Two .out of four -signs present 7t.. EMMF. Takig neurolept.ic, A .- .,. Per-sistn perkftisoniijm aftr'6-'months with,nio Yet drug ttreatment.e r 4p~ ~~~Ye No1 Positive faily -history ? >.OA* POSTENCEPI{ALITIC Yes PAR KiCNONDS .DRUG.INDUCIPARKj'JON SD Conside nderlying * 7 e~meni X demeibtift :I NoO http://www.bmj.com/ drijO Wittm*.Airad* Sornpbrgzeply vi Md~~~~~~~~~~~~~~N~~~~~~~~~~~7 0 Tretmen Persists after~~~~~~~~~~~~~~~i drug withdrawal? dF(I~~~~r& L'IbyoddptWn' N o ,.',., .. Y es~~~~~~~~~~~~~~~~~~~3 on 26 September 2021 by guest. Protected copyright. -ffi. N . I'- .'. -1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~f'' O- .. I, . ..:. -.. 4. I Symtv ai osuiyes .u- . ..:' hypot~~~~~0nsloiiwtho No *5%mwoprmpnton ..l. ..-- .. a.- :,.. OWIN G .* ,. adequfl4 iopamine -I., * .34. RI~NSO!, DSEASE . '5,, --l NoLewy bodies found. -at ner o .: .., .. I BRITISH MEDICAL JOURNAL VOLUME 293 9 AUGUST 1986 381 Br Med J (Clin Res Ed): first published as 10.1136/bmj.293.6543.379 on 9 August 1986. Downloaded from Parkinson's disease I lm~ o http://www.bmj.com/ on 26 September 2021 by guest. Protected copyright. 0 0* d.0 0 Indicates that these features, while not characteristic of * - .- idiopathic Parkinson's disease, may nevertheless be present in some cases 382 BRITISH MEDICAL JOURNAL VOLUME 293 9 AUGUST 1986 Br Med J (Clin Res Ed): first published as 10.1136/bmj.293.6543.379