Use of Dalfampridin in Primary Lateral Sclerosis

Inclusion Criteria:

1. Male or female, aged 18-99;

2. Diagnosis of upper motor neuron disease, compatible with PLS but may include upper
motor neuron (UMN) predominant ALS, defined as only upper motor neuron (UMN) features
in at least 2 body regions on examination.

3. EMG within 3 months of enrollment with minimal or no evidence of lower motor neuron
disease,

4. Time from symptom onset > 18 months

5. No previous allergy to dalfampradine

6. No current or exposure to any therapeutic agent targeting PLS or ALS within 30 days of
enrollment.

7. Must have a forced vital capacity (FVC) ≥ 60% of expected

8. Written informed consent prior to screening is present.

9. Subjects on a stable dose of or have not taken Riluzole for at least thirty days

10. Impaired walking as measured by a Hauser Index of greater than 1 and less than 7 (2 to
6, inclusive);

11. Mini Mental Status Score > 22 and deemed by the PI of being capable of providing
informed consent and following trial procedures.

12. Geographically accessible to the site.

13. Women must not be able to become pregnant (e.g., post-menopausal, surgically sterile,
or using adequate birth control methods) for the duration of the study and three
months after study completion. Adequate contraception includes: abstinence, hormonal
contraception (oral contraception, implanted contraception, injected contraception or
other hormonal contraception, for example patch or contraceptive ring), intrauterine
device (IUD) in place for ≥ 3 months, barrier method in conjunction with spermicide,
or another adequate method.

Exclusion Criteria:

1. History of clinically significant liver disease, renal disease, peripheral neuropathy,
serious peripheral vascular disease, known HSP or + C9orf72 or SPG4 mutation, or any
other medical condition felt to be exclusionary by the investigator;

2. Unwillingness to sign informed consent or any other reasons for which the investigator
feels the subject cannot complete the study;

3. Women who are pregnant, breastfeeding, or trying to become pregnant;

4. Active cancer within the previous 2 years, except treated basal cell carcinoma of the
skin;

5. Subjects taking any other experimental drugs within 30 days prior to enrollment;

6. Patient has any history of seizures; brain surgery, brain implants, any metallic
implants above the neck, cardiac pacemakers, cochlear implants, piercing or body
modification above the neck, known history of TMS related complications or
side-effects, tinnitus.

7. Patient has moderate or severe renal impairment as defined by a calculated creatinine
clearance of ≤50 mL/minute;

8. Patient has been administered botulinum toxin in the lower extremities within 6 months
prior to the screening visit and/or is expected to receive botulinum toxin in the
lower extremities during the course of the study;

9. Patient has a known allergy to pyridine-containing substances or any of the inactive
ingredients of the dalfampridine tablet (colloidal silicon dioxide, hydroxypropyl
methylcellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol,
and titanium dioxide);

10. Patient has a history of drug or alcohol abuse within the past year;

11. Patient has clinically significant abnormal laboratory values.

12. Anything else that, in the opinion of the SI, would place the subject at increased
risk or preclude the subject's full compliance with or completion of the study.