Hospitals
Intraoperative monitoring has been shown to reduce the costs associated with surgically induced neurological deficits. Our services help give your surgeons the feedback they need to ensure the best possible surgical outcomes and patient care possible.
Partnering with hospitals to deliver superior intraoperative monitoring services at the local level, NW Monitoring provides individualized solutions that meet your OR objectives. Built on exceptional customer service, we establish a long-term supply chain partnership with facilities with our technicians providing the consistency and 24-hour dependability necessary to run an efficient OR. Our scheduling team ensures you have the monitoring coverage your surgeons need so nothing falls through the cracks, and our in-house billing department works diligently with insurance companies to reduce and often eliminate patient responsibility.
Unlike larger, impersonal IOM companies, NW Monitoring is privately owned which means you will always be working with a familiar associate to get the intraoperative monitoring services you need.
Monitoring Modalities
Below you will find the modalities that we can monitor intraoperatively as well as the structures monitored.
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Brainstem evoked potentials are obtained by stimulating the auditory system with click stimuli. The neural action potentials between the cochlea and the medial geniculate body are evaluated based on the brainstem evoked response. Brainstem evoked responses are sensitive to disturbances of the auditory nerve and to retractor disturbances of the brainstem.
Monitorable Structures
Cranial Nerve VIII
Auditory Brainstem Pathways
Surgical Applications
Acoustic Neuroma Surgery
Microvascular Decompression of cranial nerves
Posterior Fossa Surgery
Skull Base Surgery Requiring Brainstem Retraction
Vestibular Nerve Section
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Language, motor, and sensory areas of the exposed cortex can be identified by direct brain recording or stimulation. The somatosensory response is recorded from the surface of the brain. Language areas are determined by verbal responses during brain stimulation in the awake patient. Motor areas of the cortex and the internal capsule are determined from EMG and evoked by electric brain stimulation.
Monitorable Structures
Motor Cortex and Internal Capsule
Language Areas of the Brain
Sensory Cortex
Surgical Applications
Brain Tumor Surgery
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On going EEG activity from the scalp is recorded from a multi-electrode array and subjected to a fast Fourier transform (FFT) analysis producing a frequency/power spectrum that can be monitored to assess changes in the metabolic state of cortical structures.
Monitorable Structures
Cortex
Surgical Applications
Aneurysm (including cerebral aneurysm
Carotid endarterectomy
Cardiopulmonary bypass
Evaluation of anesthetic effects
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Blood flow velocity is measured from intracranial arteries using Doppler ultrasound. This technique is used to detect emboli, vasospasm and inadequate blood flow to cortical structures. Microvascular Doppler can also be used to directly assess blood flow within and through an aneurysm.
Monitorable Structures
Middle Cerebral Artery
Aneurysm Feeder Arteries
Surgical Applications
Aneurysm Surgery (Cerebral and Ascending Aortic)
Carotid Endarterectomy
Cardiopulmonary Bypass
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Near-infrared absorption measurements are used to calculate an index of cerebral venus oxygen saturation
Monitorable Structures
Cortical Perfusion
Surgical Applications
Cardiopulmonary Bypass
Carotid Endarterectomy
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Visual evoked potentials are obtained from flash stimulation of the eye, and are measured from the occipital region. They may provide useful information regarding the function of the pre-chiasmal visual pathways, but are labile and require careful anesthetic control. Additionally, retrochiasmal functional changes are difficult to assess using flash visual evoked potentials.
Monitorable Structures
Optic Nerve Fuction Anterior to Chiasm
Surgical Applications
Transsphenoidal Pituitary Tumor Surgery
Posterior Cerebral Artery Aneurysm
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Somatosensory evoked responses are obtained by stimulating a peripheral nerve at the wrist and/or ankles. The propagation of the sensory action potentials is evaluated along their pathways to the cortex. This modality gives information about the integrity of the sensory pathways. It is also highly correlated with preservation of the spinal cord motor pathways.
Monitorable Structures
Spinal Cord
Lumbar and Sacral Nerve Roots
Monitoring Metabolic Function of Cortical Structures
Brainstem Somatosensory Pathways
Surgical Applications
Spinal Deformity Surgery
Spinal Cord Tumor Surgery
Cervical and Thoracic Decompression, Fusion, and/or Instrumentation Surgeries
Aortic Aneurysm
Lumbosacral Decompression, Fusion Surgeries
Cauda Equina Surgery
Sacral-iliac Fracture Reduction
Carotid Endarterectomy
Cerebral Aneurysm Surgery
Skull Base Surgery Requiring Retraction
Acetabular Fracture
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Motor Evoked Potentials are obtained by transcranial electric stimulation of the cortical motor areas. Monitoring the evoked muscle responses or the descending potentials from the spinal cord (The “D” wave) can assess the integrity of the motor pathways.
Monitorable Structures
Spinal Cord Motor Pathways
Surgical Applications
All Spinal Surgeries that Place the Spinal Cord at Risk Including:
Spinal Cord Tumor Surgery
Spinal Deformity Surgery
Cervical or Thoracic Decompressions,, Fusion and/or Instrumentation Surgeries
Thoracoabdominal aortic aneurysm
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Spinal Nerve Roots: Spontaneous EMG monitoring warns of potential nerve damage during manipulation. Evoked EMG stimulation of the pedicle screws can indicate a misdirected screw placement.
Cranial Nerves: The evaluation of spontaneous and evoked electromyogenic activity can be extremely useful in monitoring cranial nerve function. Spontaneous activity in the distribution of these nerves can signal mechanical disturbance of the cranial nerve.
Peripheral Nerves: The function of peripheral motor nerves can be evaluated during surgery by means of spontaneous and evoked electromyographic activity.
Monitorable Structures
Spinal Motor Roots
Cranial Nerves III, IV, V, VI, VII, IX, X, XI, and XII
All Peripheral Motor Nerves
Surgical Applications
Cauda Equina Surgery
Cervical or Lumbosacral Decompression
Pedicle Screw Instrumentation Surgery
Acoustic Neuroma
Anterior Neck Procedures
Mastoidectomy
Microvascular Decompression of Cranial Nerves
Parotid Surgery
Middle Ear Surgery
Skull Base Surgery When Motor Cranial Nerves are at Risk
Thyroidectomy
Vestibular Nerve Section
Monitoring of Femoral and Sciatic Nerve Function during Acetabular Surgery
Peripheral neuroma Surgery