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Neurosciences Institute


EEG | EMG | EP | Humphries Visual Field | Transcranial Doppler

Geisinger's team of neurophysiology specialists offers the full spectrum of neurophysiological testing. These tests help neurologists observe and measure the electrical activity in the brain and nervous system. Procedures such as electroencephalograms (EEG), evoked potentials (EP), and electromyograms (EMG) play an important role in diagnosing epilepsy, sleep apnea, migraine headaches, strokes and carpal tunnel syndrome.

Technologists perform the tests and record the information, then a specialty-trained physician interprets the results and reports the findings to your referring physician. Together with you and your primary care physician, Geisinger neurologists will develop a plan of care suited to your lifestyle.

Electroencephalogram (EEG)
Electroencephalograms (or EEGs) are used to detect abnormalities related to electrical activity from the brain. An EEG tracks and records brain wave patterns and is useful in confirming a diagnosis of epilepsy and evaluating dementia.

Geisinger's EEG neurophysiology lab features:

  • Five physicians, fellowship-trained in epilepsy, with subspecialty training in electroencephalography (EEG)
  • A team of registered neurophysiology technologists
  • Long-term inpatient monitoring beds with video support for:
    • Epilepsy monitoring
    • Evaluation for spells of uncertain etiology with video, EKG and EEG monitoring
    • Medication adjustment
  • Outpatient/ambulatory EEG long-term monitoring
  • Epilepsy surgery performance and planning with:
    • Brain mapping and planning for lesion removal in areas of eloquent cortex
    • Vgal nerve stimulator for epilepsy
  • Physicians who can evaluate and manage demanding and complex disorders
  • Hospital management for neurological services (including ICU for ventilator and cardiovascular support for status epilepticus and refractor seizure management)
  • Same-day reports
  • Neurologist on call 24 hours a day

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Electromyograms (EMG)
Electromyograms (or EMGs) are used to detect diseases that damage muscle tissue, nerves or the junctions between nerves and muscle. An EMG can be used to find the cause of weakness, paralysis or muscle twitching.

Geisinger's EMG neurophysiology lab features:

  • Four physicians, fellowship-trained in neuromuscular disease, with subspecialty training in electromyography (EMG)
  • Board-certified electrophysiology technicians
  • Physicians who can evaluate and manage demanding and complex disorders like myasthenia gravis, ALS/Lou Gehrig's disease, inflammatory myopathies and immune mediated neuropathies
  • Neurologist on call 24 hours a day
  • Comprehensive Botox evaluation and management for movement disorders of the face, neck and limbs as well as for spasticity. Dynamic/EMG-guided Botox injections
  • Muscular Dystrophy Clinic including:
    • Adult and pediatric care
    • Nursing support
    • Genetic testing
    • In-clinic geneticist and genetic counseling
    • Social support/financial assistance through the MDA
    • Laboratory/Bench research from the Weis Research Center
  • Hospital management of neurological diseases (including ICU for ventilator and cardiovascular support for acute/debilitating diseases like GBS and MG)
  • Same-day reports

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Evoked Potential Tests (EP)
Evoked Potential tests (or EPs) are used to evaluate and record how quickly and completely nerve signals reach the brain.

Geisinger offers the following types of Evoked Potential testing:

  • Visual evoked response - the eyes are stimulated by looking at a test pattern
  • Auditory brain stem evoked response - hearing is stimulated by listening to a test tone
  • Somatosensory evoked response - the nerves of the arms and legs are stimulated by an electrical pulse

EPs are used for diagnosing MS an other neurological disorders where a neurological examination alone does not provide enough evidence.

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Humphries Visual Field Tests (available at GMC only)
Humphries Visual Field tests use repeated light stimulus of varying intensities across the entirety of your visual field. Your sensitivity to these lights is measured and charted while your eye is focused on a single, centralized spot.

Humphries Visual Field tests are especially beneficial in diagnosing MS, pituitary gland disorders, secondary occurrences of stroke and in preparation for Blepharoplasty (eye lid surgery).

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Transcranial Doppler
Transcranial Doppler studies are used to measure the velocity, or speed, in which the blood flows through the brain's blood vessels. This test is often used in conjunction with other tests, including MRI, MRA, carotid duplex ultrasound and CT scans.

Transcranial Doppler studies help physicians diagnose carotid stenosis, arteriovenous malformations (AVMs) and cerebral circulatory arrest.

Geisinger's Neurophysiology specialists also offer Intraoperative Neuromonitoring (IONM). This testing is used during surgeries that involve risk to the nervous system. Any variation in the signals can identify an area that is associated with increased risk of postoperative loss or deterioration of function.

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