Pure dysarthria due to anterior internal capsule and/or corona radiata infarction: a report of five cases.

Abstract

SUMMARY Five cases with a sudden onset of dysarthria in the setting of hypertension are presented. No case had limb weakness or other neurological deficits. Computed tomographic scan demonstrated a small low density lesion in the anterior part of the internal capsule or the adjacent corona radiata. All cases showed a good recovery from dysarthria within two to four weeks.Since computed tomographic scan (CT scan) was introduced, small infarcts have attracted the interest of many neurologists, for the various symptoms produced. In a recent review, Fisher' summarised the lacunar syndromes; however, the site of the lesion responsible for the pure dysarthria syndrome, one of the lacunar syndromes he originally described, remains uncertain. In this report, we present five cases with pure dysarthria, in which a small low density lesion was demonstrated by CT scan. In all instances, the lesion was in the anterior part of the internal capsule or the adjacent corona radiata. Case reportsCase I A right-handed 52 year old man with untreated hypertension for one year, presented on 1 May 1984, because he had had difficulty in speaking since 29 April. On examination his blood pressure was 170/1 10 mm Hg; he had impaired articulation with slurred speech with nasal features, but no dysphagia. Weakness of the tongue was not detected. Soft palate movements were well preserved. No facial palsy. There was neither weakness nor ataxia in his limb movements. Tendon reflexes were normal and symmetrical. Plantar responses were flexor; however, the left palmomental reflex was positive. CT scan performed on 7 May, 9 days after the onset, revealed a small low density area at the right genu of the Address for reprint requests: Dr I Ozaki, Third

Pure dysarthria, isolated facial paresis, or dysarthria-facial paresis syndrome.

“…The facial paresis in this syndrome is generally mild and transient and therefore may be unnoticed by conventional neurological testing, especially when the patients are not examined early enough. It should be noted that some of the previously reported patients with pure dysarthria 5 or isolated facial paresis 4 and our 2 patients with pure dysarthria (patients 1 and 5) were not examined in an acute stage of stroke.…”

Clinical anatomic study of pure dysarthria.

“…Previous reports of this syndrome are uncommon, 4 -5 and no pathologic verification has been obtained. Ozaki et al 5 presented five cases of the pure dysarthria syndrome with computed tomography correlations. Lacunar infarcts in the anterior limb of the internal capsule were present in four cases, and an infarct in the genu was seen in one case, similar to the findings in our study.…”

Cerebral Blood Flow in Pure Dysarthria

“…In our cases frontal cortical hypoperfusion reflected dysfunction of these regions, possibly due to interruption of thalamocortical and corticothalamic fibers as well as frontopontine and frontobulbar tracts. 3,8,17 A problem remaining to be solved is whether PD is a distinct lacunar syndrome. Some authors regarded PD as a variant of dysarthria-clumsy hand syndrome.…”

“…16,17 Bilateral anterior opercular lesions cause facio-pharyngoglosso-masticatory palsy with dysarthria and dysphagia (Foix-Cavany-Marie syndrome), and a mild form of this syndrome can be produced by unilateral anterior operculum damage. 13,16,18 The frontopontine and frontobulbar tracts, including descending fibers from the anterior operculum, pass through the genu and anterior and posterior limbs of the IC, 3,4,18 while the corticospinal tract occupies the most posterior part of the IC posterior limb. These clinicoanatomical facts favor the idea that multiple lacunar infarctions involving the IC-CR can disrupt neural connections with the anterior operculum.…”

“…2,11 In previous clinicoanatomical studies of PD, lesions responsible for PD were centered in the IC and CR, and IC lesions tended to involve the anterior limb, genu, and anterior parts of the posterior limb. 1,[3][4][5]12,13 Other lesion sites associated with PD have included the basal ganglia, pons, bulbar motor cortex, and cortical regions supplied by the middle cerebral artery. 4,5,13 Some of these cases resulted from bilateral lesions.…”