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

A Pilot Study of Repetitive Transcranial Magnetic Stimulation for Improvement of Apathy 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. Apathy is a frequent complication of ALS, affecting up to 30% of patients and affecting negatively the survival. Repetitive Transcranial Magnetic Stimulation (rTMS) is a noninvasive method of modulation of brain plasticity with confirmed beneficial effect on apathy in several neurologic and psychiatric conditions. The purpose of this study is to compare the effectiveness of rTMS in improving the apathy in patients with ALS with placebo stimulation.

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. Apathy is a frequent complication of ALS, which negatively influences quality of life (caga et al. 2018) and is an independent poor prognostic factor for survival (Caga et al. 2016). Similarly, the depression is also a frequent complication of ALS. Repetitive Transcranial Magnetic Stimulation (rTMS) is a noninvasive method of modulation of brain plasticity with confirmed beneficial effect on apathy in several neurologic and psychiatric conditions like mild cognitive impairment (Padala et al. 2018), stroke (Sasaki et al. 2017), Alzheimer disease (Nguyen et al. 2017) and schizophrenia (Prikryl et al. 2013). The purpose of this study is to compare the effectiveness of rTMS in improving the apathy in patients with ALS with placebo stimulation and - as a secondary outcome - depression 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 apathy and of depression 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)
• Moderate or severe depression defined as the score in Beck's Depression Inventory ≥20
• 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