To determine the efficacy and safety of adjunctive open label Zonegran treatment in patients with refractory partial seizures.

Inclusion Criteria:

1. Male or female patients aged 18-75.
2. Able and willing to give written informed consent in accordance with the ICH GCP Guidelines.
3. Female subjects of childbearing potential must not be pregnant (as confirmed by negative serum βHCG at screening and negative urine pregnancy test at baseline/during the study), must not be lactating and must use a medically acceptable form of contraception during the study and for at least 1 month after discontinuation of study drug. Medically acceptable contraception as defined here is the oral contraceptive pill, surgical sterilization or hormonal intrauterine device in place for at least 3 months. Women who are less than 2 years post-menopausal are considered to be of childbearing potential.
4. Focal epilepsy, with simple and/or complex partial seizures with or without secondary generalized seizures as defined by the ILAE criteria.
5. Patients with a minimum of 4 partial seizures in the 8 weeks preceding the baseline visit as adequately recorded using a seizure diary card.
6. Patients should be receiving at least 1 but no more than 2 other AEDs as concomitant medication, and the dosage should be stable for at least 8 weeks before the baseline visit.

Exclusion Criteria:

1. History of status epilepticus within the last 5 years.
2. Patients with known significantly impaired renal function and/or severe hepatic impairment to the extent that the protocol dose titration schedule cannot be followed. Note Investigators should consult included SmPC as a guide.
3. Patients suffering from clinically significant psychiatric illness, psychological or behavioral problems which could interfere with study participation.
4. Patients with a history (within the last 12 months) of alcohol or drug abuse or dependency.
5. Patient suffering from any CNS progressive disease that may confound study interpretation, any active CNS infection, demyelinating disease or degenerative neurological disease.
6. Patients with a significant drug sensitivity or significant allergic reaction to any drug including sulfonamides.
7. Subjects considered by the Investigator to be an unsuitable candidate for receiving Zonegran or considered unlikely to comply with the protocol.
8. Any patient contraindicated for Zonegran treatment as per attached SmPC.
9. Any patient who is pregnant and/or lactating.