Primary Lateral Sclerosis, Report of a Case and Bibliography Revision

Introduction: Primary lateral sclerosis is a rare disease involving the upper motor neuron, producing a bulbospinal spasticity. The course of the disease is insidious and progressive, usually starting with the lower extremities, and later becoming a tetrapyremidal syndrome. As a rare disease, diagnosis in most cases is exclusionary, and the patient should be studied extensively, clinically, including a thorough medical history, laboratorial and with the relevant cabinet studies. Classic Case: It is male patient who starts his clinical picture about a year ago with weakness in left pelvic limb, subsequently accompanied by pain and paresthesias, manifesting the same symptomatology later in the contralateral leg and upper left limb. Currently is added index and middle toe hypoesthesia, moderate tremor in left arm, with the contrast of the middle toe over the ring of said hand. It has an inability to lift light objects for short periods of time, as well as fatigue in short periods of time when performing daily activities, which greatly limits their daily life. Conclusion: Motor neurone diseases are divided into two groups, and in the case studied, the upper motor neuron is exclusively affected. As it is a rare disease, with a low incidence, multiple differential diagnoses will be considered before concluding in it, considering it a diagnosis of exclusion. The natural history of the disease will always have a grim outcome, with poor prognosis for life and function, despite the measures taken to change the course of the disease.