Repetitive Transcranial Magnetic Stimulation as Therapy for Depression in Amyotrophic Lateral Sclerosis

A Pilot Study of Repetitive Transcranial Magnetic Stimulation for Improvement of Depression in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of central and peripheral motor neurons. ALS leads to death usually within 3 to 5 years from the onset of the symptoms. Available treatment can prolong the disease duration but cannot modify the disease course. Depression is a frequent complication of ALS, which further decreases quality of life and the available data concerning effectivity of antidepressant drugs are conflicting. Repetitive Transcranial Magnetic Stimulation (rTMS) is a noninvasive method of modulation of brain plasticity with confirmed antidepressive effect. The purpose of this study is to compare the effectiveness of rTMS in improving the depression in patients with ALS with placebo stimulation. Intervention will include 10 daily sessions. In each session 3000 magnetic pulses will be administered over the left dorsolateral prefrontal cortex. Assessment depression severity will be made before and after therapy, as well as two and four weeks later.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of central and peripheral motor neurons. ALS leads to death usually within 3 to 5 years from the onset of the symptoms. Available treatment can prolong the disease duration but cannot modify the disease course. Depression is a frequent complication of ALS, which further decreases quality of life and the available data concerning effectivity of antidepressant drugs are conflicting. Similarly, the apathy may also complicate ALS and worsen the prognosis. Repetitive Transcranial Magnetic Stimulation (rTMS) is a noninvasive method of modulation of brain plasticity with proved antidepressive effect in patients suffering from major depression and in depression associated with several neurological disorders such as Parkinson's disease or stroke.

The purpose of this study is to compare the effectiveness rTMS in improving the depression and - as a secondary outcome - the apathy and daily functioning in patients with ALS.

Intervention will include ten daily sessions of rTMS. In each session 3000 magnetic pulses will be administered over the left dorsolateral prefrontal cortex. Stimulation intensity will equal 120% of the motor threshold value for the right first dorsal interosseus.

Assessment of depression severity and of apathy and daily functioning will be made before and after therapy, as well as two and four weeks later.

Inclusion Criteria:

• Diagnosis of definite or probable ALS according to el Escorial criteria (Brooks et al. 2000)
• Depression defined as the score in Beck's Depression Inventory ≥14
• Mini-Mental State Examination score ≥26

Exclusion Criteria:

• Psychiatric symptoms, which may negatively influence patient's tolerance and adherence to therapy
• Respiratory insufficiency and other complications od advanced stages of ALS, which may compromise patient's ability to undergo the study procedure
• Contraindications for rTMS as listed by the Guidelines of the International Federation of Clinical Neurophysiology (Rossi et al. 2009) i.e. seizure in the past, epilepsy, presence of magnetic material in the reach of magnetic field, pregnancy, likelihood to get pregnant, intracranial electrodes, cardiac pacemaker or intracardiac lines, frequent syncopes