Patient description: The patient is a 16-year-old girl recently diagnosed with myasthenia gravis, class IIa. She complains of diplopia and weakness affecting in her upper extremities. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She is on acetylcholinesterase inhibitor treatment combined with immunosuppressants. But she still has some symptoms. She does not smoke or use illicit drugs. She is not sexually active, and her menses are regular. Her physical exam and lab studies are not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 2.0-25.0,  Niemann-Pick Disease, Type C1 Aged greater than or equal to 2 and less than or equal to 25 years old at time of enrollment, either gender and any ethnicity. 2. Diagnosis of NPC1 based upon one of the following: 1. Two NPC1 mutations; 2. Positive filipin staining and at least one NPC1 mutation; 3. Vertical supranuclear gaze palsy (VSNGP) in combination with either: i. One NPC1 mutation, or ii. Positive filipin staining and no Niemann-Pick Type 2 (NPC2) mutations. 3. Patients with at least one neurological manifestation of NPC1. For example, but not limited to, hearing loss, vertical supranuclear gaze palsy, ataxia, dementia, dystonia, seizures, dysarthria, or dysphagia. 4. Ability to travel to the National Institutes of Health Clinical Center (NIH CC) repeatedly for evaluation and follow-up. 5. If taking miglustat, the patient must have been taking a constant dose of the medication for no less than 3 months prior to baseline evaluation and must be willing to maintain that dose level for the duration of the trial. 6. Willing to discontinue all non-prescription supplements, with the exception of an age-appropriate multivitamin. 7. Women of reproductive age must be willing to use an effective method of contraception for the duration of the trial. 8. Willing to participate in all aspects of trial design including serial blood and cerebrospinal fluid (CSF) collections  Aged below 2 or above 25 years of age at enrollment in the trial. 2. Subjects will be excluded if their weight would result in an endotoxin level that would exceed 0.2 EU/kg for either the saline or drug dosing. 3. Severe manifestations of NPC1 that would interfere with the patient's ability to comply with the requirements of this protocol. 4. Neurologically asymptomatic patients. 5. Patients who have received any form of cyclodextrin in an attempt to treat NPC1. Treatment with another drug preparation for another medical indication that contains cyclodextrin as an excipient, will not a patient. 6. History of hypersensitivity reactions to cyclodextrin or components of the formulation. 7. Pregnancy or breastfeeding at any time during the study. 8. Patients with suspected infection of the CNS or any systemic infection. 9. Spinal deformity that would impact the ability to perform a lumbar puncture 10. Skin infection in the lumbar region 11. Neutropenia, defined as an absolute neutrophil count (ANC) of less than 1,500. 12. Thrombocytopenia (a platelet count of less than 75,000 per cubic millimeter). 13. Evidence of disturbed circulation of CSF. 14. Contraindication for anesthesia. 15. Prior use of anticoagulants or history/presence of a bleeding disorder with increased risk of clinical bleeding or an international normalized ratio (INR) greater than 2. 16. Patients with clinical evidence of acute liver disease having symptoms of jaundice or right upper quadrant pain. 17. Presence of anemia defined as two standard deviations below normal for age and gender. 18. For subjects 18 years of age and older, the epidermal growth factor receptor (eGFR) is automatically calculated and reported by the NIH CC laboratory utilizing the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Creatinine 2009 equation. We will subjects greater than or equal to 18 years of age if eGFR is less than or equal to 60 mL/min/1.73 m2. For subjects < 18 12 years of age, we will utilize the national kidney disease education program (NKDEP) calculator (http://www.nkdep.nih.gov/lab-evaluation/gfr-calculators/children-conventional-unit.sh tml). Results are reported as > 75 mL/min/1.73 m2 or lower. We will subjects < 18 years of age if eGFR is less than or equal to 75 15 mL/min/1.73 m2 19. Hematuria on a single urinalysis, as defined by the American Urological Association (AUA) as five or more red blood cells per high-power field (or > 25/micro L) on microscopic evaluation of urinary sediment from a properly collected urinalysis specimen. The patient will not be excluded if 2 subsequent urine specimens are negative for hematuria as defined by the AUA. 20. Proteinuria (1+ protein on urinalysis) unless evaluated and classified as benign by patient s primary medical provider or by NIH nephrology consult or in the context of normal urine protein creatinine ratio and in the absence of clinical symptoms (edema, hypertension). 21. Active pulmonary disease, oxygen requirement or clinically significant history of decreased blood oxygen saturation, pulmonary therapy, or requiring active suction. 22. Patients unable to complete a behavioral audiologic evaluation including pure-tone threshold assessment (500 Hz to 8000 Hz) to monitor for ototoxicity and for whom otoacoustic emissions (OAEs) cannot be reliably obtained at baseline. 23. Patients with ongoing seizures, that are not stable in frequency, type or duration over a 2 month period prior to enrollment, requiring change in dose of antiepileptic medication (other than adjustment for weight) over a 2 month period prior to enrollment, or requiring 3 or more antiepileptic medications to control seizures. 24. Patients, who in the opinion of the investigators are unable to comply with the protocol or have specific health concerns that would potentially increase the risk of participation