Is photic driving response normal?

Is photic driving response normal?

Normal photic driving has long been known to be potentially reduced on the side of a lesion. Posterior destructive lesions are particularly likely to attenuate the driving response, but some reports have described an enhanced photic response on the side of dysfunction.

What frequency is photic driving prominent?

The photic driving response and the photic hypersensitivity are similar as both are induced by light stimulation. The photic driving response in a high-stimulation region of 15 Hz or more (an H-response) is thought to be abnormal, and migraine patients frequently show the H-response during the interictal phase [4].

What is a posterior driving response?

40), it is usual to observe the so-called driving response over the posterior regions of the head. This response consists of rhythmic activity that is time-locked to the stimulus and has a frequency identical or harmonically related to that of the flickering light.

What is hyperventilation and photic stimulation?

Hyperventilation and photic stimulation are useful additions to a placebo-based suggestive seizure induction protocol in patients with psychogenic nonepileptic seizures. Epilepsy Behav.

What does photic driving mean?

Exposing a subject to flashing lights during an electroencephalographic (EEG) recording.

What is photic driving EEG?

In electroencephalograms (EEG), photic driving is known as a reaction to visual stimulation. Both photophobia and photic driving response are present during light stimulation. We hypothesized that cortical response to photic stimulation would differ between migraine patients with and without aura.

What is the meaning of photic?

1 : of, relating to, or involving light especially in relation to organisms. 2 : penetrated by light especially of the sun the photic zone of the ocean.

What does it mean when an EEG is abnormal?

An abnormal EEG means that there is a problem in an area of brain activity. This can offer a clue in diagnosing various neurological conditions.

What does it mean to have slow brain waves?

Focal slow wave activity on the EEG is indicative of focal cerebral pathology of the underlying brain region. Slowing may be intermittent or persistent, with more persistent or consistently slower activity generally indicating more severe underlying focal cerebral dysfunction.

What is EEG PDR?

Objective: Pivotal studies of the normal EEG posterior-dominant rhythm (PDR) typically relied on visual inspection of a few seconds of EEG data from a relatively small number of subjects in each age category.

What is Photomyogenic response?

A photomyogenic response (old term, photomyoclonic response) is character- ized by brief, repetitive muscle potentials over the anterior portions of the head and is maximal in the Fp1 and Fp2 elec- trodes. A photomyogenic response is not cerebral in origin but is muscle artifact.

What is posterior dominant rhythm?

When the patient is relaxed with eyes closed, the background is usually characterized by the posteriorly dominant alpha rhythm, also known simply as the posterior dominant rhythm. … The alpha rhythm, or alpha, is attenuated in amplitude and frequency and often completely ablated by eye opening.

What is LGS syndrome?

Lennox-Gastaut syndrome (LGS) is a type of epilepsy. Patients with LGS experience many different types of seizures including: Tonic – stiffening of the body. Atonic – temporary loss of muscle tone and consciousness, causing the patient to fall.

What is hyperventilation in EEG?

Hyperventilation (HV) is an activation technique used during EEG recording to elicit epileptiform abnormalities, and in some cases seizures, in order to enhance the diagnostic sensitivity of EEG.

Can flickering lights cause seizures?

Photosensitive seizures are triggered by flashing or flickering lights. These seizures can also be triggered by certain patterns such as stripes. Photosensitive seizures can fall under several categories, including tonic-clonic, absence, myoclonic and focal seizures.

What does Phat mean slang?

slang. : highly attractive or gratifying : excellent a phat beat moving through my body Tara Roberts.

What zones are photic?

Let’s learn them! Photic Zone is the top layer, nearest the surface of the ocean and is also called the sunlight layer. In this zone enough light penetrates the water to allow photosynthesis. The Disphotic Zone is found just below the Photic Zone and is known as the twilight layer.

What is the difference between the photic and aphotic zone?

photic zone, surface layer of the ocean that receives sunlight. … The bottommost, or aphotic, zone is the region of perpetual darkness that lies beneath the photic zone and includes most of the ocean waters.

Which is better EEG or MRI?

In general, MRI is good at telling us where the lesion is, whereas EEG is good at separating normal and abnormal primarily cortical function. The topologic usefulness of EEG is limited, although it may be improved with computerization.

Why would a neurologist order an EEG?

Why it’s done An EEG can determine changes in brain activity that might be useful in diagnosing brain disorders, especially epilepsy or another seizure disorder. An EEG might also be helpful for diagnosing or treating the following disorders: Brain tumor. Brain damage from head injury.

Can an EEG show mental illness?

Electroencephalography (EEG) is a non-invasive investigation that can aid the diagnosis of psychiatric and neuropsychiatric disorders. A good predictor of an abnormal EEG recording is the presence of an organic factor identified during the clinical assessment.

Does an EEG show past seizures?

The EEG generally records brain waves between seizures, called interictal brain waves. These waves may or may not show evidence of seizure activity.

What are the symptoms of temporal lobe damage?

Damage to the temporal lobes can result in:

Can you have an abnormal EEG without having epilepsy?

To complicate this further, some people have ‘abnormal’ EEGs but do not have epilepsy. Also, many people who do have epilepsy will only have ‘abnormal’ activity on the EEG if they have a seizure at the time the test is happening.