Acquired hemidystonia in childhood: A clinical and neuroradiological study of thirteen patients

ELSEVIER

Acquired Hemidystonia in Childhood: A Clinical and Neuroradiological Study of Thirteen Patients Nardo Nardocci, MD*, Giovanna Zorzi, MD*, Marina Grisoli, MD*, Viviana Rumi, MD*, Giovanni Broggi, MD*, and Lucia Angelini, MD*

A retrospective study of 13 patients (4 males/9 females) with acquired hemidystonia in childhood is reported. The mean age of onset of hemidystonia was 6.4 years (range 1-13.4 years); the mean duration of dystonia at the time of last follow-up was 11.4 years (range 3.6-23 years). Hemidystonia was caused by ischemic infarction in 9 patients and was attributed to perinatai trauma in 1; in 4 of the 9 patients with stroke and in the remaining 3 patients laboratory investigations were suggestive of p r i m a r y antiphospholipid syndrome. Eleven of the 13 patients had delayed onset of dystonia: between 1 month and 8.9 years (mean 3.4 years). Ten patients had neuroradiological evidence of contralateral basal ganglia damage. A history of hemiparesis and evidence of striatal damage on CT or MRI were important risk factors for the development of dystonia. Response to medical treatment (trihexyphenidyl dose as high as 40 mg daily) in 5 patients was disappointing; 4 of the 5 patients who underwent functional stereotaxic operations were improved, but dystonia was still present at the end of the follow-up. Our study provides additional evidence that lesions of the striatum may induce dystonia, supporting the theory of striatopallido-thalamic disconnection. Furthermore, our resuits indicate that the occurrence of delayed dystonia must be considered in the diagnostic approach to childhood-onset dystonia. Nardocci N, Zorzi G, Grisoli M, Rumi V, Broggi G, Angelini L. Acquired hemidystonia in childhood: A clinical and neuroradiological study of thirteen patients. Pediatr Neurol 1996;15:108-113.

From the *Departments of Child Neurology; *Neuroradiology; and *Neurosurgery; National Neurological Institute "C. Besta"; Milan, Italy.

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Introduction Dystonia is a clinical syndrome characterized by involuntary sustained posturing and movements of different parts of the body. According to etiology, dystonia can be classified as idiopathic or symptomatic [1]. Dystonia affecting unilateral arm, leg, and face is termed hemidystonia [2]; this clinical presentation is often symptomatic and has etiologic significance [3,4]. In most hemidystonic patients, pathological and neuroradiological studies reveal focal lesions involving the basal ganglia, suggesting a pathogenetic mechanism of dystonia [3]. We report etiologic factors, clinical features and neuroradiological findings in a series of 13 patients with acquired hemidystonia in childhood. Two of these patients were reported previously as separate cases [5]. Patients and Methods The 13 children in the present study were selected from a larger group of young patients with dystonia observed during the last 15 years at the National Neurological Institute of Milan; they presented dystonia affecting unilateral arm and leg and were thus classified as hemidystonic [2]. None had a positive family history or history of exposure to drugs or other agents known to produce persistent dystonia. Patients with evidence of associated metabolic defects were excluded. Clinical and radiological data were evaluated retrospectively. All the patients were filmed. CT scan studies were performed on all patients at least twice; MR examinations were performed in 6 patients. Antiphospholipid antibodies (aPLs), detected as lupus anticoagulant (LAC), and anticardiolipin antibodies (aCLs), were assessed in all patients during the follow-up at least twice. The interval between the cerebral insult and the first aPLs determination ranged from 2 months to 15 years (mean 6 years, 2 months). Laboratory investigations included leukocyte count, hemoglobin level, platelet count, erythrocyte sedimentation rate, kidney and liver function tests, electrolytes, serum glucose, serum total proteins and electrophoresis, quantitative serum immunoglobulins, total and high density lipopro-

Communications should be addressed to: Dr. Nardocci; Department of Child Neurology; National Neurological Institute "C. Besta"; Via Celoria 1l; 20133 Milan, Italy. Received November l, 1995; accepted May 1, 1996.

© 1996 by Elsevier Science Inc. All rights reserved. P[I S0887-8994(96)00152-X ° 0887-8994/96/$15.00

tein (HDL) cholesterol, triglycerides, serum complement levels (C3 and C4), urine analysis, VDRL, Coombs' test for autoimmune hemolysis, cryoglobulins, rheumatoid factor, and antinuclear and antinative DNA antibodies. Coagulation studies included prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, antithrombin III, protein C, and protein S. LAC Screening. aPTT was determined by mixing 0.1 ml plasma, 0.1 ml diluted (1:4) thrombofax reagent (Ortho Diagnostic System, Raritan, NJ) and 0.1 ml 2% kaolin suspension in Michelis buffer pH 7.4. After 10 min incubation at 37°C, 0.1 ml 0.025 M CaC12 was added and clotting time was recorded. When a prolonged aPTT was detected, the assay was performed with a mixture of 50% patient's plasma and 50% pooled normal plasma. A prolonged clotting time of the mixture indicated the presence of a circulating anticoagulant. In such case, the test was repeated with the patient plasma and, for comparison, pooled normal plasma with or without 0.1 ml thrombofax (1:8 dilution) as a platelet substitute. The shortening of a prolonged aPTT upon thrombofax addition was considered evidence of the presence of LAC. In patients with a normal aPTT, the kaolin clotting time or the dilute Russell's viper-venom time was determined [6,7]. These tests are more sensitive than aPTT and do not provide false-positive results. aCL Assay. Serum aCL were detected by an immunosorbent assay as previously described [8]. Upper normal limits for either lgG or IgM aCL levels were set at the mean normal values plus 5 SD of a group of 42 normal control samples. The lgG and IgM antibody levels were expressed as arbitrary units (AU) with reference standard serum samples [9]. Serum samples with lgG values less than 8 AU or IgM values less than 6 AU were defined as negative; values between 8 and 14 for IgG and between 6 and 14 for IgM were defined as positive at low level, values between 15 and 50 for both IgG and IgM as positive at moderate level, and values greater than 50 AU for both lgG or IgM as positive at high level. No standard reference serum samples were available for titration of IgA aCL. According to the proposed criteria for APS [10], only patients with either positive LAC test or positive IgG and/or IgM aCL at a moderate/ high level (/> 15 AU) in two determinations performed more than 8 weeks apart were considered positive for aPLs. The time interval between the two determinations was 3 to 6 months. Five patients underwent stereotaxic thalamotomy for the correction of abnormal movements. Pre- and postoperative (15 days, 6 months, 1 year, and subsequently every year) standard neurological and neurofunctional evaluation with videotape recording and self-assessment was performed in all patients [ 11]. Postoperative status was rated on a score that was the sum of the scores for the neurological, neurofunctional, and selfassessment evaluation (10-12 = very good, 7-9 = good, 4-6 = fair, 1-3 = minimal, I) = no change). The target points of the operations were the nucleus ventralis oralis anterior (Voa) and ventralis oralis posterior (Vop) of the thalamus and the zona incerta (lateral thalamotomy). Detailed technical data were reported previously [11]. The results of medical treatment were evaluated by the Fahn and Marsden Disability and Severity Scale of Dystonia [12].

Results

Our 13 patients (4 males, 9 females) represent 6% of all dystonic patients observed during the reported time. The historical data, clinical features, and neuroradiological findings are summarized in Table 1. At present, the age of the selected patients ranges from 6 years 6 months to 33 years 5 months (mean age 18 years 10 months). The mean age at onset of hemidystonia was 6 years 4 months (range 1 year to 13 years 4 months). The mean duration of dystonia at the time of last follow-up was 11 years 4 months (range 3 years 6 months to 23 years). The dystonic symptoms were represented by dystonic postures and dystonic movements in 11 patients (patients

1-3 and 5-12); the remaining 2 patients (patients 4 and 13) presented action dystonia. Eleven patients (patients 1-10 and 13) had focal neurological deficits before onset of dystonia, in the form of spastic hemiparesis. The mean time between the onset of focal signs and the appearance of dystonia was 3 years 4 months (range 1 month to 8 years 9 months). One patient (patient 11) manifested gradual onset of dystonic postures of left hand and arm with concurrent homolateral sensory symptoms lasting 1 week, followed by involvement of the leg and foot in 4 months. Patient 12 manifested sudden onset of dystonic postures of the left limbs, with rapid movements of high amplitude in addition to the abnormal posturing of the left arm. Hemidystonia was caused by ischemic infarction in 9 patients (patients 1-4 and 6-10) and was attributed to perinatal trauma in patient 5. In 4 of the 9 patients with stroke (patients 3, 7, 8, 10) and in the remaining 3 patients (patients 11-13), positive aPLs at a moderate titer (IgG and/or IgM) were observed in two different determinations. None of the patients had thrombocytopenia, false-positive VDRL test, cryoglobulins, positive Coombs' test, or antinuclear or antinative DNA antibodies. None of the patients developed any clinical or serological evidence of systemic lupus erythematosus (SLE) or other systemic disease at the end of follow-up. None of the patients experienced a recurrence of stroke during follow-up. Neuroradiology. CT scans showed hypodense lesions located in the basal ganglia contralateral to hemidystonia in 10 patients (patients 1-10). In 4 of these patients (patients 3, 8, 9, and 10), the lesion involved the head of caudate and putamen and spared the globus pallidus (Figs 1 and 2); in the remaining 6 patients (patients l and 2 and 4-7), it was difficult to distinguish lesions of the putamen from those of the globus pallidus; however, the lesions were often situated laterally, involving the head of the caudate and the putamen more than the globus pallidus, and none appeared to involve the globus pallidus alone. The basal ganglia lesions were associated with involvement of the genu of internal capsule in 4 patients (patients 2, 3, 5, and 6) and of the external capsule in 1 (patient 2). Cerebral hemiatrophy homolateral to basal ganglia lesions were detected in 7 of the 10 patients (patients 1, 2, 5-7, 9, and 10). CT scan was normal in 3 (patients 11-13). MRI was performed in 6 (patients 7 and 8, and 10-13). The examination confirmed the isolated involvement of putamen and head of caudate in patients 8 and 10 and the involvement of the globus pallidus in patient 7 (Fig 3). Homolateral hemiatrophy was present in patients 7 and 10. In none of these patients was additional involvement of thalamus or brainstem disclosed. In patient 12, who had a normal CT scan, MRI showed a slight diffuse signal hyperintensity in the periventricular white matter of the right hemisphere and the posterior portion of the internal capsule, not confirmed by the Ti-weighted images. In patients 11 and 13, MRI did not demonstrate any abnormalities. Medical Treatment. Five patients (patients 1 and 8-1l)

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Table 1.

Clinical and neuroradiological findings of the 13 patients

Patient/Sex/ Age at presentation (yr, mo) 1/M/29,4

2/F/20,11

3/F/16,2

4/M/22,7

5/F/27,4

6/M/15,5

Predisposing factors 3 yr 10 mo: sudden onset of R hemiparesis and aphasia 4 years: sudden onset of vomiting, drowsiness, and L hemiparesis 4 yr: sudden onset of R hemiparesis and aphasia 5 yr 11 mo: sudden onset of R hemiparesis Born at term after a delivery complicated by forceps extraction: R hypomotility and hemiparesis observed during the first year of life 7 mo: sudden onset of R hemiparesis

Latency between the Predisposing Brain Insult and Onset of Dystonia 2 mo

Age at Onset of Dystonia

Type of Dystonia

R arm, hand, foot

Dystonic movements and postures

13 y r 4 mo

L arm, hand, trunk, leg, foot

4 yr 3 mo

8 yr 3 mo

1 mo

6 yr

9 yr

4 yr

Distribution of Dystonia

Follow-up (yr)

Topography of Lesion by CT (Hypodensity) or MRI

19

L lenticular nucleus, L hemiatrophy

Dystonic movement and postures

7

R arm, hand, trunk, leg, foot R ann, hand, foot

Dystonic movements and postures Action dystonia

8

R fronto-capsulolenticular, R external capsule, R hemiatrophy L putamen and head of L nucleus caudate

12

L lenticular nucleus

18 mo

1 yr 6 mo

R arm, hand, leg, foot

Dystonic movements and postures

25

L capsulolenticular, L hemiatrophy

4 yr

4 yr 7 mo

R ann, hand, leg, foot

7

L capsulolenticular, L hemiatrophy

10 yr 9 mo

L arm, hand, foot

Dystonic movements and postures Dystonic movements and postures Dystonic movements and postures

15

R capsulolenticular, R hemiatrophy

2

L putamen and head of L nucleus caudate

21

L putamen and head of the L caudate, L hemiatrophy Head of the L caudate, L hemiatrophy

7/M/18,4

2yr: sudden onset of L hemiparesis

8 y r 9 mo

8/F/12,6

6 yr: sudden onset of partial motor seizures, followed by aphasia and R hemiparesis 4 yr 2 mo: sudden onset of R hemiparesis Born at term after a delivery complicated by vacuum extraction; prolonged neonatal jaundice; at 3 mo hypomotility of the upper right limb was observed and was followed by involvement of ipsilateral leg at age 8 mo Gradual onset of dystonic postures of L hand and arm, followed involvement of leg and foot within 4 mo 6 yr 7 mo: sudden appearance of dystonic posture of L lower limb, rapidly followed by abnormal posturing of left arm with superimposed rapid movement of high amplitude 4 yr 8 too: sudden onset of L hemiparesis

7 mo

6 yr 7 mo

R hand, leg, foot

1 mo

4 yr 3 mo

R arm, hand, foot

2 yr

2 yr

R arm, hand, leg, foot

13 yr

L arm, hand, trunk, foot

Dystonic movements and postures

6 yr 7 mo

L arm, hand, leg, foot

Dystonic movements and postures

Slight diffuse hyperintensity in the periventricular white matter of R hemisphere and posterior portion of R internal capsule

4 yr 9 mo

L arm, hand, leg, foot

Action dystonia

Normal

9/F/33,5

10/F/17,6

1 I/F/16

12/F/10,6

13/F/6,6

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--

--

1 mo

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Dystonic movements and postures Dystonic movements and postures

8

3.4

Normal

Transient side effects occurred in 3 patients: a contralateral hemiparesis disappearing after a few days in 2 children (patients 1 and 9) and mood depression, lasting 2 months, in patient 10. No side effects were observed in long term follow-up. In all patients, significant relief of dystonia was observed immediately after operation; the symptoms subsequently worsened. At the last evaluation, the results of thalamotomy were considered good in patients 1 and 2, fair in patients 5 and 9, and as "no change" in patient 10. The more responsive symptoms were dystonic movements; dystonic postures were diminished to a lesser extent. Discussion

Figure 1. Patient 3. CT: Axial section shows the hypodensity in the left putamen and slight hypodensity of the head of the left caudate nucleus (arrow). GIobus pallidus is preserved.

received anticholinergic therapy (trihexyphenidyl) in dosages as high as 40 mg daily. Patient 1 experienced a subjective improvement; the remaining 4 (patients 8-11) received no benefit from the therapy and the treatment was discontinued after 1 year. Patients 3 and 4 achieved a partial spontaneous remission, and patient 13 recovered completely by 6 months after onset of the symptoms. Surgical Treatment. Five patients (patients 1,2,5,9, and 10) underwent unilateral stereotaxic thalamotomy at age ranging from 10 to 23 years. The duration of hemidystonia at the time of operation varied from 2 to 19 years. The mean postoperative follow-up was 6 years 6 months (range 2 years 7 months to 13 years).

Figure 2. Patient 10. CT: Axial image shows only slight hypodensity in the head of the left caudate nucleus (arrow). The lenticular nucleus has a normal aspect.

In our series, 10 of 13 patients developed hemidystonia as a consequence of a contralateral basal ganglia lesion. Preexisting spastic hemiparesis and radiological evidence of striatal damage were important risk factors for the development of dystonia. Early reports indicated a relation between basal ganglia lesions and abnormal movements of athetoid or dystonic type [13]. Dooling and Adams demonstrated striatal damage in the brain of 4 patients with "posthemiplegic athetosis." They suggested that any lesion capable of isolating the striatum from the ventralis anterior, the centrum medianum and ventralis lateralis nuclei of the thalamus, preserving the corticospinal pathways, could result in contralateral involuntary movements [14]. Subsequently, isolated reports revealed occasional striatal lesion detected by CT scan in hemidystonic patients. Finally, Pettigrew and Jankovic [4] and Marsden et al. [3] demonstrated a strict correlation with CT-documented basal ganglia lesions in a series of hemidystonic patients. Our data are in concordance with those observations, suggesting that lesions of the striatum may induce dystonia and provide additional evidence for the theory of striato-pallido-thalamic disconnection. Hemidystonia in childhood has been reported in relation with cerebrovascular disease [5,15-19], perinatal trauma [3,4,13,14,16,20], presumed encephalitis [4,14], head trauma [3,4,16,21-24], tumor [25-27], and storage disorders [4]. In our series, the most frequent cause of hemidystonia was ischemic infarction in the basal ganglia (9 of 13). Dystonia is a rare complication of cerebrovascular disease in the basal ganglia territory in adults [28-30]. Hemidystonia as a consequence of stroke appears to occur more often in children than in adults, possibly due to an aberrant neuronal sprouting during brain maturation [14,16]. In 4 of the 9 patients with ischemic infarction of the basal ganglia (patients 2, 3, 7, and 10), positive aPLs in two different determinations were detected, with no evidence of SLE or other systemic disease, suggesting the diagnosis of PAPS [31,32]. Our data are in concordance with the high prevalence of aPLs in idiopathic stroke of childhood reported by other researchers [33-35]. APLs

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IlI

a

b

Figure 3. Patient 7. MRI: Axial (a) 7~ (TR: 2, lO0, TE: 100) and co~wnal (b) Tz-weighted images (TR: 400, TE: 15, 90 '~) show the signal abnormali(v c)]'the right lenticular nucleus and of the head gf the caudate nucleus. The right frontal horn is enlarged.

were also detected in patients 11-13, who presented acute onset and unilateral distribution of dystonia with no radiological evidence of a vascular disorder. Normal MRI or angiographic examinations have been reported in chorea and hemidystonia related to PAPS; in those patients, motor symptoms were attributed either to a vascular disorder involving small vessels of basal ganglia or to an immunemediated insult to basal ganglia neurons triggered by aPLs [5,33,36,37]. Similar mechanisms could have accounted for the movement disorder observed in our patients, despite the absence of demonstrable imaging abnormalities in basal ganglia. The diffuse alteration of white matter observed in patient 12 might be due to a cross-reactivity of aPLs with cerebral phospholipids, which might have mediated a demyelinating process. This pathogenethic mechanism has been hypothesized in collagen-vascular diseases [31]. PAPS should therefore be considered in the diagnosis of acquired hemidystonia in childhood, even in the absence of a neuroradiologically documented brain lesion. In 1 patient in our series (patient 5), hemidystonia was attributed to birth anoxia; perinatal brain damage appears to be the least frequent cause of acquired hemidystonia, as reported in the literature [3,4]. In our series, all but 2 patients demonstrated a delay between the brain injury and the onset of dystonia. Delayed-onset dystonia appears to be a frequent consequence of basal ganglia lesion occurring in childhood, as reported by other researchers [3,4,16,20,24]. The longest delay, to 32 years, was reported in a patient with dystonia due to perinatal cerebral anoxia [4]. The delay observed in our patients was 1 month to 8 years 9 months, showing wide variability. Our data do not permit demonstration of a correlation between the duration of the delay and the etiology or the age of occurrence of brain lesion; moreover, we observed no significant differences between duration of the delay and the clinical characteristics of dystonia or

112 PEDIATRICNEUROLOGY Vol. 15 No. 2

the extent of the lesion observed on CT/MRI. Delayedonset dystonia is difficult to explain and has been suggested to be the result of slowly evolving aberrant neuronal sprouting subsequent to a static lesion in the developing brain [ 16]. None of our patients showed progression of dystonia during follow-up, but delayed-onset dystonia due to a "static" encephalopathy can present a spreading of symptoms beyond the site of initial involvement in a period of months to years [16,20]; this possibility must be considered in the diagnosis of childhood-onset dystonia. Patients 3 and 4 obtained a spontaneous reduction and patient 13 obtained complete relief of dystonia during follow-up. This clinical course does not appear to be related to etiology, age of occurrence of the brain lesion, or presence or extent of the brain lesion. Two of these patients (patients 4 and 13), however, did not present dystonic movements or postures at rest but manifested dystonia only on action, which is the typical pattern of action dystonia. This clinical presentation could be related to a more favorable clinical course, but the small number of observations does not allow us to make definitive conclusions. The response of anticholinergic treatment in our patients was disappointing: Trihexyphenidyl at dosages as high as 40 mg daily provided only transient or no improvement in motor performances. Similar observations have been reported by other investigators [4,24]; however, Saint Hilaire et al. described good efficacy of trihexyphenidyl at a higher dosage (to 60 mg daily) in a series of 10 patients with delayed-onset dystonia due to perinatal or early childhood asphyxia [20]. The literature on the efficacy of stereotaxic thalamotomy for the correction of abnormal movements in childhood is quite extensive [11,38-42]. Variable benefits are reported, but hemidystonic patients have not been separately evaluated. All our study patients who underwent

operation obtained marked reduction of dystonia immediately after the operation; dystonia later worsened, but at the end of follow-up (6 years 6 months) 4 out of the 5 patients manifested a reduction of dystonia. We thank the Associazione "Paolo Zorzi" for Neuroscience for financial support.

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