Focal Delta Activity: Causes & Reasons

Possible Causes for Focal Delta Activity

A brain concussion is a still incompletely defined syndrome of traumatic brain injury (TBI) that causes a spectrum of symptoms without evident structural damage to the brain. A headache, cognitive deficits, emotional instability, sleep disturbances, and an overall change in mental state after trauma are highly[…] [symptoma.com]

Traumatic Brain Injury

Objective: To explore the relationship between three QEEG global indexes and their association with functional outcome after neurorehabilitation in non-acute acquired brain injury (ABI) patients (traumatic brain injury and stroke). Methods: Twenty-one adult ABI patients in post-acute phase were studied. Delta-alpha[…] [pubmed.ncbi.nlm.nih.gov]

Meningioma

Overview A meningioma is a tumor that arises from the meninges — the membranes that surround the brain and spinal cord. Although not technically a brain tumor, it is included in this category because it may compress or squeeze the adjacent brain, nerves and vessels. Meningioma is the most common type of tumor[…] [mayoclinic.org]

Brain Neoplasm

Stereotactic radiosurgery (SRS) using the Gamma Knife (GK) is now being increasingly utilized for the treatment of brain metastases. However, there are a few reported cases of SRS-induced brain neoplasms. We herein report the case of a Japanese woman with metastatic non-small cell lung cancer (NSCLC) harboring[…] [ncbi.nlm.nih.gov]

Encephalitis

BACKGROUND: Autoimmune-mediated processes are the driving force behind many neurological diseases. Autoimmune encephalitis, a group of syndromes, mediated by or at least associated with autoantibodies against neuronal tissue, have gained increasing importance especially in paediatric neurology. Since the first NMDAR[…] [ncbi.nlm.nih.gov]

Temporal Lobe Tumor

[…] broad sharp delta activity over the area of the tumor. [karger.com]

Slow wave activity Focal delta (EEG frequency < 4 Hz) activity is the classic electrographic sign of a local disturbance in cerebral function; however, if the lesion is small [emedicine.medscape.com]

This rhythmic activity contrasts with the usual arrhythmic slowing seen focally with brain tumor and may conceivably be related to the rhythmic slowing associated with seizure [karger.com]

Focal Epilepsy - Speech Disorder - Mental Retardation

Space Occupying Lesion Most common finding is focal 4-7 Hz theta with sh/sp focal activity and focal delta activity. [studystack.com]

Focal Abnormality The most important is delta activity, which can be caused by tumor, infarct, abscess, subdural hematoma, hemorrhage, etc. [studystack.com]

Stroke CVA (specifically) Focal slowing or polymorphic delta activity in area of involved blood vessel. Possible PLEDS or contralateral sz may develop. [studystack.com]

Rasmussen Syndrome

Focal delta activity without epileptiform spikes may preceed the onset of epilepsia partialis continua by several months. [pediatricneurologybriefs.com]

Figure 1: A-Electroencephalogram- Slow-wave activity- delta waves in the right cerebral hemisphere, B and C- RNM-FLAIR Coronal / T2 Axial- Cortical-subcortical atrophy of [smjournals.com]

[…] to the possibility of adult-onset Rasmussen´ssyndrome in the differential diagnosis of patients with progressive hemiparesis, cognitive deterioration and drug-resistant focal [smjournals.com]

Focal Seizure

delta activity occurred in a majority of electroencephalograms (EEGs). [ncbi.nlm.nih.gov]

[…] tumor was more common when intelligence and results of neurological examination were each normal, a plausible cause for uncontrolled seizures was lacking, and persistent focal [ncbi.nlm.nih.gov]

Anti-NMDA Receptor Encephalitis

delta rhythm (6 cases, 9.7%), focal slowing (5 cases, 8.1%), and diffuse beta activities (4 cases, 6.5%). [ncbi.nlm.nih.gov]

Most patients have extensive EEG abnormalities characterized by generalized or focal slow activity in the delta–theta range, sometimes with superimposed epileptic activity [doi.org]

Patients with normal background, epileptiform discharges, polymorphic delta rhythm, and diffuse beta activity in EEG all had favorable long-term outcome. [ncbi.nlm.nih.gov]

Idiopathic CD4 Lymphocytopenia

EEG showed diffuse slowing of the back ground activity and focal polymorphic delta activity over the left temporal region and no periodic discharges. [neurologyindia.com]

Metabolic Encephalopathy

[…] and delta), presence of particular EEG patterns (focal or generalized), intermittent activity suppression, or an electrocortical silence. [35], [36] In the patients with [neurologyindia.com]

[…] lesions; seizure activity; EEG of metabolic encephalopathy is liable to have diffuse slowing in the delta-theta frequencies, while degenerative disease may cause little [dartmouth.edu]

delta/theta activity, as well as focal paroxysms of sharp waves and spike-waves during hyperventilation (HV). [38] In patients with cirrhosis, in addition to diffuse slow [neurologyindia.com]

Uremic Encephalopathy

delta/theta activity, as well as focal paroxysms of sharp waves and spike-waves during hyperventilation (HV). [38] In patients with cirrhosis, in addition to diffuse slow [neurologyindia.com]

activity (theta and delta), triphasic waves with bifrontal predominance may be registered. [neurologyindia.com]

Stroke

In some cases, focal slow activity may presents as focal and irregular slow activity in the delta frequency, receiving the designation of polymorphic delta activity (PDA) [scielo.br]

Thalamic lesions generally produced focal or unilateral delta activity, but the slow activity varied in time of onset, amplitude and degree of focality 16. [scielo.br]

It was first described by Walter 14, in 1936, who proposed the term "delta waves" for focal slow activity associated with tumors involving cerebral hemispheres. [scielo.br]

Uncinate Seizure

focal fast activity like our case. [j-epilepsy.org]

[…] in almost 50%; in the majority of those that do show abnormalities, focal attenuation or rhythmic theta or delta is the prominent rhythm, and 10% of the abnormalities are [j-epilepsy.org]

[…] brief events in one night, usually in the space of a few hours. 10 Video-EEG recordings of NFLE show striking stereotypy between attacks. 7 Ictal EEG shows no epileptiform activity [j-epilepsy.org]

Infratentorial Tumor

When unaccompanied by delta activity, theta is less likely to indicate a lesion that produces a focal neurological deficit or seizures. [emedicine.medscape.com]

With further progression, delta activity increases in voltage while frequency becomes slower and distribution wider. [emedicine.medscape.com]

Juvenile Myoclonic Epilepsy

activity and temporal lobe-onset seizures. [ncbi.nlm.nih.gov]

In this rare case of coexistent primary generalised epilepsy and focal epilepsy, the epileptic networks of the two forms of epilepsy appear to overlap. [ncbi.nlm.nih.gov]

[…] myoclonic epilepsy, to the novel appearance of interictal temporal spikes immediately preceding bisynchronous discharges, and subsequently to temporal intermittent rhythmic delta [ncbi.nlm.nih.gov]

Hypoxic-Ischemic Brain Injury

In some cases, focal slow activity may presents as focal and irregular slow activity in the delta frequency, receiving the designation of polymorphic delta activity (PDA) [scielo.br]

Thalamic lesions generally produced focal or unilateral delta activity, but the slow activity varied in time of onset, amplitude and degree of focality 16. [scielo.br]

It was first described by Walter 14, in 1936, who proposed the term "delta waves" for focal slow activity associated with tumors involving cerebral hemispheres. [scielo.br]

Temporal Lobe Epilepsy

activity and temporal lobe-onset seizures. [ncbi.nlm.nih.gov]

The monomorphic slow waves are without clinical correlate and must be differentiated from the polymorphic delta activity that would be seen with a focal lesion over the temporal [hindawi.com]

In this rare case of coexistent primary generalised epilepsy and focal epilepsy, the epileptic networks of the two forms of epilepsy appear to overlap. [ncbi.nlm.nih.gov]

Epilepsy with Generalized Tonic-Clonic Seizures

delta waves or attenuation (27%), spikes (27%) or attenuation (9%) in tonic seizures; rhythmic beta activity (66%) or rhythmic theta-alpha activity (33%) in focal tonic-clonic [scielo.br]

GTC seizures associated with encephalopathic generalized epilepsy (EGE) have slow background activity, voltage asymmetries, and intermixed focal or generalized theta and delta [neupsykey.com]

Ictal EEG in focal seizures consisted of spikes (66%) or rhythmic theta-alpha activity (33%) in tonic-clonic seizures with secondary generalization; rhythmic spikes (73%), [scielo.br]

Encephalopathy

[…] and delta), presence of particular EEG patterns (focal or generalized), intermittent activity suppression, or an electrocortical silence.[35],[36] In the patients with hypoglycemia [neurologyindia.com]

[…] lesions; seizure activity; EEG of metabolic encephalopathy is liable to have diffuse slowing in the delta-theta frequencies, while degenerative disease may cause little [dartmouth.edu]

/theta activity, as well as focal paroxysms of sharp waves and spike-waves during hyperventilation (HV).[38] In patients with cirrhosis, in addition to diffuse slow activity [neurologyindia.com]

New-Onset Refractory Status Epilepticus

[…] complex resembling delta brushes (figure 3); a characteristic seizure onset pattern with focal fast activity with shifting seizures.53 There is no comparable study in adults [pn.bmj.com]

Seizures are brief and infrequent at the onset, associated with focal fast beta activity with a gradual evolution to SE characterized by rhythmic spike and wave complexes [ncbi.nlm.nih.gov]

A retrospective study in children with FIRES identified three common early patterns: initially infrequent seizures gradually evolving into status epilepticus; a beta-delta [pn.bmj.com]

Idiopathic Generalized Epilepsy

Other characteristic EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, and photoparoxysmal response. [ncbi.nlm.nih.gov]

The EEG signature of IGE is bisynchronous, symmetric, and generalized spike-wave complex; although focal, irregular, and so called "fragments" of discharges are not uncommon [ncbi.nlm.nih.gov]

Locked-in Syndrome

Some subjects showed minor focal or bilateral disturbances in the theta or fast delta range. [neurology.org]

An alpha-like rhythm may occur in truly comatose patients, but this activity usually is reported to be unresponsive to most alerting stimuli. [neurology.org]

Preeclampsia

The pattern is usually a diffuse slowing of activity (theta or delta waves), sometimes with focal slow activity and occasional paroxysmal spike activity. [health.am]

Postictal State

However, the same study found that patients who appeared “confused” were much more likely to have either bisynchronous spike-and-slow-wave discharges or diffuse delta activity [ncbi.nlm.nih.gov]

[…] lesions; seizure activity; EEG of metabolic encephalopathy is liable to have diffuse slowing in the delta-theta frequencies, while degenerative disease may cause little [dartmouth.edu]

[…] than focal discharges [14]. [ncbi.nlm.nih.gov]

Paroxysmal Exertion-Induced Dyskinesia

Activity Associated w/ white matter lesions (encephalopathy or Deg dz or acute focal injury) Arrhythmic, irregular activity that persists Polymorphic, irregular, and persistent [quizlet.com]

(IRDA)Intermittent Rhythmic Delta Activity asociated with deep or midline structures by direct compression or increase IVH pressure (not ICP) Delta frequency, medium-to-high [quizlet.com]

[…] occipital slowing w/ superimposed alpha attenuates w/ the alpha rhythm when eyes open or the child alerts does not exceed alpha rhythm's amplitude by >1.5x (PDA)Polymoprhic Delta [quizlet.com]

California Encephalitis

Focal neurologic findings were present in 20% and electroencephalograms revealed asymmetrical delta-wave activity in 40% of the children during the acute phase of the illness [jamanetwork.com]

Toxic Encephalopathy

[…] lesions; seizure activity; EEG of metabolic encephalopathy is liable to have diffuse slowing in the delta-theta frequencies, while degenerative disease may cause little [dartmouth.edu]

delta/theta activity, as well as focal paroxysms of sharp waves and spike-waves during hyperventilation (HV). [38] In patients with cirrhosis, in addition to diffuse slow [neurologyindia.com]

Benign Familial Infantile Epilepsy Type 4

With decreasing seizure frequency after 4 months of age, the EEG evolved into generalized slow delta activity and only occasional spikes (18 weeks); after 6 months of age [karger.com]

[…] the EEG showed low voltage undifferentiated activity with frequent ictal pattern and occasional focal spikes and sharp waves. [karger.com]