Hypophonia as a sign of thalamus lesion: a case report

Abstract

Hypophonia is a neurological sign usually seen after brainstem or peripheral damage, either at the recurrent laryngeal nerve or vocal cord level. However, it has been described as a sign of supratentorial strokes in a few studies, specifically when anterior and ventral thalamic involvement is reported. In addition, it is a prominent sign of other neurological disorders such as Parkinson disease and other extrapyramidal conditions. We describe a case of hypophonia secondary to a left thalamic hemorrhage, after a careful search of other potential causes of this deficit, and we discuss the underlying neuroanatomical circuits.

Rare coexistence of multiple manifestations secondary to thalamic hemorrhage: A case report

“…Perhaps, disruptions of the thalamo-striato-cortical loop at the anterior and ventral thalamus level could explain the observed speech deficits. It is worth noting that hypophonia has been mainly reported after dominant thalamus lesions[ 7 , 10 ] while our patient suffered right thalamic hemorrhage. In a study of right-handed Parkinson’s patients, Liotti et al [ 11 ] observed activation of the right anterior insula, caudate head, putamen, and dorsolateral prefrontal cortex after successful treatment of hypophonia.…”

“…They suggested that the anterolateral thalamic lesion that disrupted extrapyramidal pathways might be a major factor in producing dysphonia and that the predominantly anterior and possibly lateral thalamic lesions were responsible for hypophonia. Recently, Rodríguez-López et al [ 7 ] presented a case report of hypophonia secondary to a left thalamic hemorrhage. They speculated that a thalamo-striato-cortical loop might play an important role in controlling voice modulation, and disruptions of this loop precisely at the anterior and ventral thalamus level would result in hypophonia.…”

“…They speculated that a thalamo-striato-cortical loop might play an important role in controlling voice modulation, and disruptions of this loop precisely at the anterior and ventral thalamus level would result in hypophonia. While the specific role of thalamic nuclei in voice modulation is still unclear, it has been proposed that, as an extrapyramidal sign, hypophonia could be explained by the loss of input from the basal ganglia and substantia nigra to the ventral anterior and the ventral lateral nuclei[ 7 ]. Our patient presented dysphasia (a hoarse voice and hypophonia) secondary to a hemorrhage lesion involving the lateral thalamus.…”

“…In a study of right-handed Parkinson’s patients, Liotti et al [ 11 ] observed activation of the right anterior insula, caudate head, putamen, and dorsolateral prefrontal cortex after successful treatment of hypophonia. This result suggest that the right thalamo-striato-cortical loop might mediate the voice modulation, and disruptions of this loop would lead to hypophonia[ 7 ]. The precise mechanisms should be illustrated in further study.…”

“…Due to its complex anatomical structure and connections, the thalamus serves as a pivotal relay center for the brain, subserving both sensory and motor mechanisms[ 3 ]. In recent years, thalamic stroke has increased in incidence worldwide[ 4 ] and commonly results in somatosensory dysfunction[ 5 ], hemiparesis[ 6 ], language deficits[ 7 ], and movement disorders[ 1 ]. However, the coexistence of these manifestations has been rarely reported.…”