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Richard P Brenner

Publications and source records attributed to Richard P Brenner.

6 recordsLinked to original sources
PubMed2006

Increasing the yield of EEG.

The EEG is the most common neurodiagnostic test performed to evaluate patients with suspected seizures. The majority of EEGs are requested in patients because of suspected seizures or for seizure management. It is unlikely that the patient's usual spell will be recorded during a routine EEG. Therefore, several activation techniques have been used in clinical EEG to help increase the occurrence of interictal epileptiform abnormalities, which are highly correlated with the diagnosis of a seizure disorder. EEG laboratories have long employed these techniques, which include hyperventilation, intermittent photic stimulation, sleep, and sleep deprivation. However, despite being utilized in routine clinical EEGs for decades, a number of differing views on the usefulness and indications for these procedures exist. This review will evaluate these procedures and review their history, technique, effectiveness, controversies, and unanswered questions.

Electroencephalography↗
PubMed2005

The interpretation of the EEG in stupor and coma.

This review discusses a variety of causes of stupor and coma and associated electroencephalographic (EEG) findings. These include metabolic disturbances such as hepatic or renal dysfunction, which are often characterized by slowing of background rhythms and triphasic waves. Hypoxia and drug intoxications can produce a number of abnormal EEG patterns such as burst suppression, alpha coma, and spindle coma. Structural lesions, either supra- or infratentorial, are reviewed. EEGs in the former may show focal disturbances such as delta and theta activity, epileptiform abnormalities, and attenuation of faster frequencies. In infratentorial lesions, the EEG may appear normal, particularly with a pontine lesion. Some patients may be encephalopathic because of ongoing epileptic activity with minimal or no motor movements. This entity, nonconvulsive status epilepticus (NCSE), is difficult to diagnose in obtunded/comatose patients, and an EEG is required to verify the diagnosis and to monitor treatment. Several EEG patterns and their interpretation in suspected cases of NCSE such as periodic lateralized epileptiform discharges (PLEDs), bilateral independent periodic lateralized epileptiform discharges (BIPLEDs), generalized periodic epileptiform discharges (GPEDs), and triphasic waves are reviewed. Other entities discussed include the locked-in syndrome, neocortical death, persistent vegetative state, brainstem death, and brain death.

Animals↗
PubMed2003

A case of area-specific stimulus-sensitive postanoxic myoclonus.

The authors report a case of area-specific stimulus-sensitive postanoxic myoclonus and discuss possible pathophysiology. A 71-year-old man sustained cardiorespiratory arrest that lasted 10 minutes and remained unresponsive. On the first EEG obtained 8 hours after the arrest there was no cerebral electrical activity before stimulation of the trigeminal-innervated areas. Periorbital stimulation was associated with bursts of spike-wave activity and generalized myoclonic jerks, whereas other types of stimulation did not elicit any response. A second EEG obtained 32 hours later showed a nonreactive alpha coma pattern. The patient died 7 days after the arrest. Area-specific stimulus-sensitive postanoxic myoclonus is very rare. The regularity of generalized bursts of spike-wave activity (cortical response) in response to stimulation of trigeminal-innervated areas suggests that the resting EEG electrocerebral silence may have been a result of cortical suppression with disinhibition of stimulus-sensitive brainstem-generated myoclonus.

Aged↗
PubMed2002

Is it status?

Nonconvulsive status epilepticus (NCSE) is difficult to diagnose in the obtunded/comatose patient. Such patients often have other serious medical conditions, and the diagnosis is frequently delayed. We review criteria for diagnosis, treatment, and prognosis of NCSE in this setting. Terms that have been used to describe SE in obtunded/comatose patients without tonic-clonic convulsions include subtle generalized SE, electrographic SE, SE in comatose patients, generalized electrographic SE, non-tonic-clonic SE, subclinical SE, and NCSE. Sometimes the same term has been used when describing different disorders, and different terms are often applied for the same entity. The incidence of NCSE in obtunded/comatose patients is uncertain. Clinically they may display subtle, intermittent focal or multifocal rhythmic movements suggestive of seizures; there may not be movements. NCSE can occur in a variety of disorders, including hypoxia, metabolic disturbances, and after convulsive seizures. A number of EEG patterns have been described in NCSE, and many of these are controversial, particularly as to whether they are ictal. These include periodic lateralized epileptiform discharges (PLEDS), bilateral independent PLEDS (BIPLEDS), periodic epileptiform discharges (PEDS), which can be either focal or generalized, and generalized triphasic waves (TWs). The diagnostic criteria for NCSE also are controversial, and there are no agreed-on criteria to diagnose NCSE in obtunded/comatose patients, nor is there consensus on how it should it be treated. Furthermore, outcome is poor, and several studies suggest that treatment may not be helpful.

Adult↗
PubMedDate not supplied

EEG in convulsive and nonconvulsive status epilepticus.

Seizures and status epilepticus (SE) are serious complications in intensive care unit (ICU) patients. SE is often divided into convulsive and nonconvulsive types, based on clinical features. The EEG is helpful in further dividing SE into those that are generalized from onset, or have a partial onset, because this may be difficult to do clinically. This is particularly true in patients with tonic-clonic seizures, which may be generalized from onset, or secondarily generalized. Rarely in the ICU, although not infrequently in epilepsy monitoring units, the EEG may indicate that the event is nonepileptic, such as pseudostatus epilepticus. Nonconvulsive SE is often difficult to diagnose, be it partial or generalized, and the diagnosis is usually delayed. Furthermore, although an EEG is required to verify the diagnosis, there are not widely accepted criteria to diagnose this entity, particularly in obtunded/comatose patients. For example, it is controversial whether several EEG patterns, such as periodic lateralized and generalized periodic epileptiforms, are ictal or interictal. This article reviews EEG findings in different types of SE in adults and provides numerous examples.

Coma↗