This 50-year-old woman noted some “pressure” in the bottom of her right foot about 4 months prior to her evaluation. In relatively short sequence thereafter, she started limping and feeling tightness in her right thigh, relieved with exercise, and clumsiness in the right leg. She reported a recent motor vehicle collision whereby she rear-ended another car as she could not move the right foot away from the accelerator promptly enough. Over the past few weeks, she has noted episodes when the right arm is drawn up with the hand clenched.

Our patient shows right foot plantar flexion and inversion activated during walking, which are relieved when the motor program changes (e.g., during marching, or when walking backward), and disappears at rest. This task-specific, action-induced phenomenon is referred to as dystonia. Most adult-onset focal dystonias occur in the upper body (cervical, cranial, or brachial regions). Onset of dystonia in the foot at the age of 50 years suggested a secondary cause and deserves further evaluations.

Additional examination findings demonstrated generalized hyperreflexia with right leg spasticity, right ankle clonus, and right weakness of proximal and distal muscles of the leg to a greater extent than the arm (see second video). These findings were consistent with an upper motor neuron syndrome. Furthermore, the presence of a jaw jerk and mild to moderate cortical sensory loss (mild right agraphesthesia and astereognosis) pointed in the direction of a left hemispheric lesion, affecting the parietal cortex and disrupting
the corticospinal system. Although a form of motor neuron disease could not initially be ruled out, a brain magnetic resonance imaging (MRI) demonstrated a large ring-enhancing lesion in the left frontoparietal region, near her motor strip (Fig. 115.1). A functional MRI showed her corticospinal track to be located along the anterior border of this lesion, which, upon stereotactic biopsy, was revealed to be a glioblastoma multiforme, World Health Organization (WHO) grade IV. Radiation and chemotherapy were initiated. Given the eloquent location of the tumor, resection of the tumor was not deemed feasible.