Evaluation and Management of Idiopathic Unilateral Foot Drop.

BACKGROUND: In this study, our purpose is to evaluate patients who were followed by acute developing single-sided foot drop and improving with conservative management or spontaneously.

METHODS: Between 2019 and 2020, 10 patients were evaluated for a unilateral weakness of the lower extremity in the form of absent dorsiflexion at the ankle joint and were given a diagnosis of foot drop without any etiological cause. Patients were followed for a period of 18 months. All patients were evaluated for acute foot drop of the affected extremity by utilizing the following diagnostic modalities, EMG, MRI lumbar spine, MRI knee, peripheral MRI neurography and non-contrast brain MRI. Each patient was evaluated for a history of Covid-19 infection over the past year. Patients with any identified cause were excluded.

RESULTS: Initial evaluation of muscle strength in all patients revealed 0/5 by the MRC muscle testing grading scale. (1) In 2 patients, the muscle strength was 3/5 at the 6th month, and in the other 8 patients 4/5 at the 6th month. The muscle strength of all patients improved as 5/5 in 1 year. Six of the patients were dispensed an AFO device and nine patient's performed physical therapy. Evaluation of EMG results identified significant neuropathy at the level of the common peroneal at the fibular head in all patients. In comparison with peroneal nerve stimulation below and above the fibular head in the lateral popliteal fossa; 50% reduction in sensory amplitude, and motor conduction slowing of >10 m/s was present. Evaluation of knee MRI revealed, no masses, edema, or anatomical variations at the level of the fibular head.

CONCLUSIONS: In patients diagnosed with unilateral acute foot drop without an etiological cause, one should keep in mind that spontaneous resolution of this condition can occur within one year period.