Cerebral Infarction Producing Sudden Isolated Foot Drop

Abstract

Foot drop usually results from lesions affecting the peripheral neural pathway related to dorsiflexor muscles, especially the peroneal nerve. Although a central nervous system lesion is suspected when there is a lack of clinical evidence for a lower motor neuron lesion, such cases are extremely rare. We describe a patient with sudden isolated foot drop caused by a small acute cortical infarction in the high convexity of the precentral gyrus. This report indicates that a cortical infarction may have to be considered as a potential cause of foot drop. Foot drop can be defined as a weakness in ankle and toe dorsiflexors.1 It usually results from lesions affecting the peripheral nervous system, from the lumbosacral radicles to the deep peroneal nerve. 1 Isolated foot drop caused by an upper motor neuron lesion is rarely reported, 2-7 and we are not aware of any report on isolated foot drop caused by cerebral infarction. We present such a patient here. CASE REPORTA 68-year-old hypertensive man visited our department complaining of weakness in dorsiflexion of the left toe and ankle that had been present for 2 days. He described having a steppage gait on walking, especially when climbing stairs. He claimed to have no history of diabetes, heart disease, stroke, alcohol abuse, or recent trauma to the left lower limb.On neurologic examination he was alert and oriented. He showed no dysarthria or dysphagia, and all cranial nerves were intact. The results from a funduscopic examination were normal. His motor strength was normal throughout the upper and lower limbs except for the weakness of the left ankle and toe dorsiflexors. Individual muscle strength testing revealed that the power of the left tibialis anterior, extensor digitorum longus, and extensor digitorum brevis power was grade II, while the left quadriceps femoris, gastrocnemius, iliopsoas, and gluteus maximus muscle strengths were within normal limits. Eversion and inversion movements of both ankles were also unremarkable. The deep tendon reflex (DTR) was normoactive in all extremities. His sensory perception of light touch, pinprick, joint po-

Cerebral Infarction Presenting with Unilateral Isolated Foot Drop

“…However, CNS pathologies can be found in some patients without any UMN symptoms, as seen in our case4,6,8). In such cases, diagnosis is delayed due to its atypical presentation which resembles a peripheral type of foot drop.…”

Yin-yang sign on magnetic resonance imaging in a child with left frontal arterio-venous malformation and foot drop

“…Bilateral foot drop following treatment of an anterior communicating artery aneurysm has also been reported [6]. In addition, isolated mono-paresis can be due to an UMN lesion secondary to a lacunar infarct and isolated foot drop has also been reported in cortical infarction [7,8].…”

Isolated foot drop due to subcortical hemorrhage

“…Foot drop due to cranial lesions are rare and most of these cases are caused by brain tumours or traumatic injuries. Acute isolated foot drop due to ischaemic or hemorrhagic stroke has rarely been reported [1]. Presented here is the case of a patient with acute foot drop due to a small cerebral hemorrhage.…”

“…Previous cases of foot drop due to cranial lesions have been reported as lesions of the parasagittal area [1], which is thought to be the foot homunculus [2]. Moreover, most of these cases were accompanied by signs of damage to upper motor neurons.…”