Indian Pediatrics 1998;35:663-665 

DOPA Responsive Dystonia in a Girl with Vitiligo

Nalin Chaudhary
Jayanti Mani
Sangeeta Rawat
Rajesh Mulye
Pravina Shah

From the Department of Neurology, K.E.M. Hospital, Parel, Mumbai 400 012, India.

Reprint requests: Dr. Nalin Chaudhary, Department of Neurology, Ward 10, K.E.M. Hospital, Parel, Mumbai 490 012, India.

Manuscript Received: September 8, 1997; Initial review completed: October 22, 1997; Revision Accepted: December 24, 1997.
 

Segawa et al. in 1976 first described a group of children who had idiopathic progressive dystonia which worsened progressively through the day and improved after sleep. The clinical features are classical: On- set in the first decade, female preponderance, predominant involvement of the legs with pes equinovarus, diurnal fluctuation and sustained responses to levodopa. Lack of awareness often leads to the condition being misdiagnosed as hysteria, hereditary spastic paraparesis or talipes deformity of the foot. We report a rare case of progressive dystonia with diurnal fluctuation associated with vitiligo in a young girl.

Case Report

A 13-year-old girl presented with history of progressive difficulty in walking since seven years. The girl was a full term normal delivery, of non consanguineous parentage. She had achieved normal milestones, but started walking at 18 months. At the age of 5 years, parents noticed hypopigmented patches over the right ankle and dorsum of foot which progressed over the next few years to involve both the lower limbs, lower trunk and the dorsum of both hands. Six months after the appearance of the first patch she had twisting of the left foot after walking about half a kilo- meter. Later it affected both the feet. Foot- wear slipped off and she fell and often hurt herself. She also had some abnormal posturing of the hands. A couple of years later, abnormal posturing of the feet appeared within a couple of hours after waking up and worsened by evening. She would be symptom free for a few minutes after an afternoon nap. Lately, the pen drops off her hand after prolonged writing. She was unable to walk even short distances due to severe dystonia. There was no history suggestive of encephalitis or jaundice in the past. She had three brothers aged 15, 10 and 8 years, who were neurologically normal.

Clinical examination revealed a men- tally normal girl without jaundice, hepatomegaly or Kayser Fleischer rings. There were irregularly shaped hypopigmented patches of various sizes distributed symmetrically over dorsum of both hands, feet and also over the face. The sensations over the patches was normal.

Both lower limbs had mildly increased tone with dystonic posturing of both feet with inversion and plantar flexion at the ankles, dorsiflexion of the left toe and pronation of the forearms. There was an action tremor in the hands. The sensations, co-ordinations and tendon reflexes were normal with flexor plantar response. The gait was awkward with lurching and stooping of the trunk and circumduction of the legs.

With a clinical diagnosis of diurnal dystonia with vitiligo, the patient was investigated. The hemogram and liver and renal bio-chemical profiles were normal. The serum ceruloplasmin, thyroid profile, plasma and urinary aminoacidograms, and serum lactate pyruvate ratio were normal. The serum anti-nuclear antibody (ANA) titer and anti-dsDNA titers were negative. MRI brain did not reveal any signal abnormalities.

The patient was given low dose of a levodopa-carbidopa combination (50 mg levodopa and 5 mg carbidopa in two divided doses in a day). She showed remark- able improvement in symptoms on follow up 4 weeks later.

Discussion

Our patient was a girl and had symptoms from the age of 6 years with asymmetric onset of dystonia in the feet and an equinovarus deformity. She later also had difficulty with writing and posturing of the hands. There was no torsion of the trunk. She responded well to levodopa. Her clinical profile was thus similar to the patients described earlier(2). Action tremors has also been described in older children. Hereditary progressive dystonia with diurnal fluctuation can be differentiated from idiopathic torsion dystonia by the earlier age of onset, female predominance, absence of torticollis and trunk torsion and its response to levodopa. A careful history with a specific inquiry about diurnal fluctuations is crucial to the diagnosis. There have been reports of misdiagnosis such as hysteria and spastic paraparesis(3). Patients have also undergone unnecessary corrective surgery for presumed talipes equinovarus deformity(4).

There is a sustained response to small doses of levodopa over many years without development of any abnormal reaction to dopaminergic neurotransmitters such as denervation supersentivity. This suggests normally functioning dopaminergic receptors.

It is believed that the dopaminergic deficit in Dopa - responsive dystonias is due to a functional disturbance in the synthesis of dopamine(5). Another hypothesis is a deficiency in the number of presynaptic dopamine reuptake sites in the striatum(6).

Vitiligo is an acquired disorder of skin pigmentation of presumed autoimmune etiology with destruction of the melanin producing cells in the skin. The auto- immune disorder Systemic Lupus Erytheinatosis (SLE) was considered as a clinical possibility which could explain the association of dystonia. with. vitiligo, but all the possible serological markers of SLE were found negative in this case. While the dystonia and the skin lesions in this patient may not be causally related, it is of interest to note that L-DOPA is the common precursor for both dopamine and melanin synthesis.
 

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