Other symptoms include

diplopia
dysphagia
vertigo
monocular vision loss
progressive dementia or stupor in patients with a nonfocal neurologic exam and minimal abnormalities on MRI (more common in AIDS patients)
facial hypoesthesia

Diagnosis
The current standard for diagnosis typically includes positive CSF cytology, vitreous biopsy, or brain/leptomeningeal biopsy. Histopathological confirmation is essential for definitive diagnosis.MRI or contrast enhanced CT classically shows multiple ring-enhancing lesions in the deep white matter. The major differential diagnosis (based on imaging) is cerebral toxoplasmosis, which is also prevalent in AIDS patients and also presents with a ring-enhanced lesion, although toxoplasmosis generally presents with more lesions and the contrast enhancement is typically more pronounced. Imaging techniques cannot distinguish the two conditions with certainty, and cannot exclude other diagnoses. Thus, patients undergo a brain biopsy or vitreous biopsy, if there is intraocular involvement. Classification
Most PCNSLs are diffuse large B cell non-Hodgkin lymphomas. Treatment
Surgical resection is usually ineffective because of the depth of the tumour. Treatment with irradiation and corticosteroids often only produces a partial response and tumour recurs in more than 90% of patients. Median survival is 10 to 18 months in immunocompetent patients, and less in those with AIDS. The addition of IV methotrexate and folinic acid (leucovorin)  may extend survival to a median of 3.5 years. If radiation is added to methotrexate, median survival time may increase beyond 4 years. However, radiation is not recommended in conjunction with methotrexate because of an increased risk of leukoencephalopathy and dementia in patients older than 60.
In AIDS patients, perhaps the most important factor with respect to treatment is the use of highly active anti-retroviral therapy (HAART), which affects the CD4+ lymphocyte population and the level of immunosuppression. The optimal treatment plan for patients with PCNSL has not been determined. Combination chemotherapy and radiotherapy at least doubles survival time, but causes dementia and leukoencephalopathy in at least 50% of patients who undergo it. The most studied chemotherapeutic agent in PCNSL is methotrexate (a folate analogue that interferes with DNA repair). Methotrexate therapy in patients with PCNSL typically requires hospitalization for close monitoring and intravenous fluids. Leucovorin is often given for the duration of the therapy. Standard chemotherapeutic regimens for lymphoma such as CHOP are ineffective in PCNSL, probably due to poor penetration of the agents through the blood brain barrier.Newer treatments, such as high dose chemotherapy combined with autologous stem cell transplant are proving to increase survival by years. New research to increase permeability of the blood brain barrier with NGR-hTNF followed by CHOP, produced responses in 75% cases. A phase 1 clinical trial of ibrutinib – an inhibitor of Brutons tyrosine kinase – in 13 patients reported responses in 10 (77%). Five of the responses were complete. Prognosis
In immunocompetent patients
The initial response to radiotherapy is often excellent, and may result in a complete remission. However, the duration of response with radiotherapy alone remains short, with median survival after treatment with radiotherapy just 18 months.