Paper

Eur. Neurol. 1988;28:164-166
Received: February 12, 1987
Accepted: June 16, 1987

Parietal Ataxic Hemiparesis
P.M.
V.
L.

Pratap M.
Vithal
Lisa

Yagnik
Dhaduk
Huen

Philadelphia VA Medical Center and The Medical College of Pennsylvania, Philadelphia, USA
Key Words
Ataxia
Hemiparesis
Parietal lobe

Abstract
Ataxia in the parietal lobe is rarely described. A case of ataxia hemiparesis due to a parietal lobe infarction is described and pathophysiology is discussed
Pratap M. Yagnik, MD, Neurology Service (127), VA Medical Center, University and Woodland Avenues, Philadelphia, PA 19104 (USA)

A combination of ipsilateral corticospinal tract signs and cerebellar ataxia was designated by Fisher [1] as ataxic hemiparesis. Pathologic study showed an old lacunar infarction
in the basis pontis at the level of junction of the upper one-third and lower two-thirds on the opposite side of the neurologic deficit. The following is a report of case of ataxic
hemiparesis with a lesion in the parietal lobe as seen on the computerized tomography (CT) scan.

Case Report
A 61-year-old white male with non-insulin-dependent diabetes mellitus developed paresthesia of the left upper limb in February, 1982. The carotid angiogram at that time showed bilateral mild atherosclerotic
changes at the carotid bifurcation. Two-dimensional echocardiography showed a clot in the anterior leaflet of the mitral valve. He was treated with intravenous heparin and later on with Warfarin for six months. He
was stable till November 2, 1985, when he developed tingling and numbness of the left upper extremity along with weakness of the left hand. On examination the patient was awake and alert. There was flattening of
the left nasolabial folds. There was slight drift of the left upper extremity with slight weakness (-5/5 on Medical Research Council Scale) of the left upper extremity. The patient had slightly impaired pain sensation
on the left upper extremity along with agraphesthesia and astereognosis. The position sense of the left fingers was slightly impaired while the vibration sense was normal. The tendon reflexes were symmetrical and
the left plantar reflex was extensor. The patient had marked finger to nose ataxia which was out of proportion to the weakness

and sensory changes. There was no significant change in the patient’s ataxia with eyes open or closed, and the Romberg sign was negative. A CT scan of the head showed a well-defined aera of decreased density in
the right parietal region consistent with ischemic infarction (fig. 1).

Discussion
Infarction found in posterosuperior part of the internal capsule, adjacent to the corona radiata, was thought to be responsible for ataxic hemiparesis in the autopsied case of Fisher
and Cole [2]. They felt that the clinicopa-thologic correlation was unsatisfactory because of presence of multiple infarctions in other locations. In 1978, Fisher [1] described three
cases of ataxic hemiparesis with an old infarct cavity in the basis pontis at the level of junction of the upper one-third and lower two-thirds on the opposite side of the neurologic
deficit. The infarct was thought to be secondary to occlusion of penetrating arteries as the basilar artery was patent in each case. All three patients were hypertensive. Subsequently
there are several reports of ataxic hemiparesis with varieties of pathologic lesions [infarction, ref. 3–14; hemorrhage, ref. 15–17; tumors, ref. 12, 14, 18] in different locations
[internal capsule, ref. 3, 4, 6, 8, 10, 11, 17; corona radiata, ref. 5, 14; thalamus, ref. 7; midbrain, ref. 18; basis pontis, ref. 9, 10, 13, 15] as shown by CT scan of the brain.

Downloaded by:
UCL
144.82.108.120 - 4/4/2017 7:29:40 AM

Parietal Ataxic Hemiparesis
165

Fig. 1. CT scan showing an infarction in the right parietal region (a, b).

In our patient the CT scan of the brain (fig. 1) showed a recent ischemic infarction in the parietal region. The patient had mild left hemiparesis with ataxia of the left upper and
lower extremities and parietal lobe signs characterized by tactile inattention, mild agraphesthesia and astereognosis. Ataxia in parietal lobe lesions has been described since 1916
[quoted by Appenzeller and Hanson, ref. 19], however, there are only infrequent reports in English language. Appenzeller and Hanson [19] described two patients with parietal
ataxias, one of whom had an infarction in the arm area of the parietal lobe in the postcentral gyrus [19]. Critchley [20] described two patients with unilateral ataxia and parietal
lobe lesion. In both cases there was no sensory loss. One patient was thought to have biparietal softening while the other patient had a large parietal lobe abscess at autopsy.
The reason for cerebellar ataxias in lesion of the parietal lobe is uncertain. Impaired proprioception is thought to be responsible for ataxia but some patients with parietal ataxia
do not have sensory impairment on clinical examination. Ataxia may be related to lack of spatial orientation in the patients with parietal lobe lesion or related to destruction of
corticopontine (parietopontine) fibers destined for the cerebellum. Also, it is believed that parietal lobe constitutes a higher center related to vestibular and cerebellar nuclei [21].
We believe that ataxic hemiparesis in our patient was due to recent infarction seen on the CT scan in the parietal area. Ataxic hemiparesis produced by the lesion in different areas
of the brain can be recognized clinically by the presence of other associated signs and symptoms and CT scan [10]. The presence of nystagmus, dysarthria
and normal sensation favors pontine localization and presence of sensory abnormalities, while absence of dysarthria and nystagmus favors supratentorial location for ataxic
hemiparesis. Ataxic hemiparesis is a syndrome caused by a variety of pathologic processes in the different regions of the brain.

References

Downloaded by:
UCL
144.82.108.120 - 4/4/2017 7:29:40 AM

1 Fisher, CM.: Ataxic hemiparesis. A pathologic study. Archs Neurol. 35: 126–128 (1978).
2 Fisher, CM.; Cole, M.: Homolateral ataxia and crural paresis: a vascular syndrome. J. Neurol. Neurosurg. Psychiat. 28: 48–55 (1965).
3 Perman, G.P.; Racy, A.: Homolateral ataxia and crural paresis: case report. Neurology 30: 1013–1015 (1980).
4 Iragui, V.J.; McCutchen, C.B.: Capsular ataxic hemiparesis. Archs Neurol. 39: 528–529 (1982).
5 Sage, J.I.; Lepore, F.E.: Ataxic hemiparesis from lesions of the corona radiata. Archs Neurol. 40: 449–450 (1983).
6 DeRenzi, E.; Nichelli, P.; Crisi, G.: Hemiataxia and crural hemiparesis following capsular infarct. J. Neurol. Neurosurg. Psychiat. 46: 516–563 (1983).
7 Bogousslavsky, J.; Regli, F.; Ghika, J.; Feldmeyer, J.: Painful ataxic hemiparesis. Archs Neurol. 41: 892–893 (1984).
8 Ichikawa, K.; Tsutsumishita, A.; Fujioka, A.: Capsular ataxic hemiparesis. 39: 585–586 (1982).
9 Van Buggenhout, E.; Dehaene, I.; Van Zandijcke, M.: Pontine ataxic hemiparesis. 41: 16 (1984).
10 Huang, C.Y.; Lui, F.S.: Ataxic hemiparesis, localization and clinical features. Stroke 15: 363–366 (1984).
11 Spertell, R.B.; Ransom, B.R.: Dysarthria-clumsy hand syndrome produced by capsular infarct. Ann. Neurol. 6: 263–265 (1979).
12 Radhakrishnan, K.; Malhotra, A.K.; Shridharan, R.: Ataxic hemiparesis: clinical, electrophysiologic, radiologic and patho166

Yagnik/Dhaduk/Huen

logic observations. Clin. Neurol. Neurosurg. 84: 91–100 (1982).
13 Sakai, T.; Murakami, S.; Ito, K.: Ataxic hemiparesis with trigeminal weakness. Neurology, New York 31: 635–636 (1981).
14 Biller, J.; Scardigli, K.: Ataxic hemiparesis from lesions of the corona radiata. Archs Neurol. 41: 136–137 (1984).
15 Schnapper, R.A.: Pontine hemorrhage presenting as ataxic hemiparesis. Stroke 13: 518–519 (1982).
16 Mori, E.; Tabuchi, M.; Yamadori, A.: Lacunar syndrome due to intracranial hemorrhage. Stroke 16: 454–459 (1985).
17 Mori, E.; Yamadori, A.; Kuda, Y.; Tabuchi, M.: Ataxic hemiparesis from small capsular hemorrhage. Archs Neurol. 41: 1050–1053(1984).
18 Bendheim, P.E.; Berg, B.O.: Ataxic hemiparesis from a midbrain mass. Ann. Neurol. 9: 405–407 (1981).
19 Appenzeller, O.; Hanson, J.: Parietal ataxia. Archs Neurol. 75: 264–269(1966).
20 Critchley, M.: The parietal lobe, pp. 160–161 (Williams & Wil-kins, Baltimore, 1953).
21 Garcin, R.: The ataxias; in Vinken, Bruyn, Handbook of clinical neurology, vol. 1, pp. 309–355 (American Elsevier, New York 1969).

00i4–3022/88/0283–0i64$2.75/0

Downloaded by:
UCL
144.82.108.120 - 4/4/2017 7:29:40 AM

© 1988 S. Karger AG, Basel