• PRIMARY LATERAL SCLEROSIS INCLUSION CRITERIA:

Patients with PLS, aged 18 and older, must meet the diagnostic criteria proposed by Pringle (1992), incorporating Santa Clara (2004) consensus for pure PLS.

Clinical:

• Insidious onset in adulthood, progressive course
• No family history
• Disease duration greater than 3 years without lower motor neuron clinical signs
• Clinical signs restricted to corticospinal/corticobulbar tract dysfunction

Imaging:

• Brain MRI normal (except cortical atrophy)
• Normal cervical spine
• Negative chest X-ray, negative mammograms in women

EMG after 3 years, but within last 3 years, showing no active denervation.

Normal serological studies for serum chemistry, Vitamin B12, Vitamin E levels, very long-chain fatty acids.

Negative serology for syphilis, Lyme disease, HTLV 1 and 2.

AMYOTROPHIC LATERAL SCLEROSIS INCLUSION CRITERIA:

Patients with ALS, aged 18 and older, must fulfill the revised El Escorial criteria for probable or definite ALS.

• Probable ALS: Upper and Lower motor neuron signs are present in more than two regions, but some UMN signs must be rostral to LMN signs.
• Definite ALS: Upper and Lower motor neuron signs are present in more than three regions.

HEALTHY VOLUNTEERS INCLUSION CRITERIA:

Healthy adults, aged 18 and older, willing to participate, and able to give informed consent.

EXCLUSION CRITERIA:

Cognitive impairment of such severity that patients cannot provide assent to participate in the protocol. During the screening examination, we will question the patients to see if they understand that they are being evaluated, the types of tests we are using, and the response required. If they are unable to answer these questions, they will be excluded from the study.

History or evidence of co-existence of a second neurological disorder, such as stroke, epilepsy, Parkinson's disease, polio, ataxia or neuropathy.

History of traumatic brain injury, skull defects or neurosurgery.

Patients who fulfill the inclusion criteria for ALS and PLS but have the following conditions will be allowed to participate in cognitive studies and EEG studies, but will be excluded from MRI testing.

• Pacemakers or other implanted electrical devices, brain stimulators, dental implants, aneurysm clips (metal clips on the wall of a large artery), metallic prostheses (including metal pins and rods, heart valves, and cochlear implants), permanent eyeliner, implanted delivery pumps, or shrapnel fragments.
• Occupational exposure to metal fragments, as in welders and metal workers, which may lead to small fragments in the eye.
• Pregnancy. Women of childbearing potential will undergo urine pregnancy testing before MRI scanning.
• Fear of confined spaces.
• Patients with paramagnetic dental crowns or joint pins will be excluded from 7T MRI scanning