seizure semiology for CLTM group Flashcards
What are auditory auras characterized by?
Simple auditory hallucinations, like hearing a ‘buzz’ or a ‘noise’.
The symptomatogenic zone is Heschell’s gyrus.
What type of hallucinations do olfactory auras typically involve?
Hallucinations of unpleasant smells.
They are frequently seen in patients with mesial temporal lobe epilepsy.
What do gustatory auras consist of?
Unpleasant taste.
The insula is the symptomatogenic zone for this aura.
What sensations are associated with autonomic auras?
Subjective sensations suggesting autonomic alterations such as palpitations, sweating, ‘goose bumps’, etc.
They may be diagnosed as ‘autonomic seizures’ with objective documentation.
What are abdominal auras usually secondary to?
Temporal lobe epilepsies.
They can also be triggered by extratemporal epilepsies.
What are examples of symptoms described in abdominal auras?
- Nausea
- Tenseness
- Squeezing
- Burning
- Sensation of warmth
- Gas or pressure
- Electric shock sensation.
These sensations usually start in the epigastrium.
What are psychic auras?
Complex hallucinations and/or illusions affecting different senses.
Examples include autoscopy, fear, elation, déjà vu, and jamais vu.
What defines autonomic seizures?
Seizures where the main symptomatology is an autonomic alteration that can be documented objectively.
Ictal tachycardia is one example.
What distinguishes simple motor seizures from complex motor seizures?
Simple motor seizures involve unnatural but simple movements, while complex motor seizures involve movements that imitate natural actions.
The distinction does not pertain to the level of consciousness.
What are myoclonic seizures?
Short muscle contractions lasting <200 ms.
They are most often seen in generalized epilepsies.
What are tonic seizures characterized by?
Sustained muscle contractions leading to ‘posturing’.
They commonly affect proximal muscle groups.
What is the typical motor sequence in generalized tonic-clonic seizures?
Starts with tonic posturing followed by a ‘jittery’ phase that transforms into clonic activity.
Symmetrical involvement of all limbs suggests generalized epilepsy.
What defines versive seizures?
Forced and involuntary turning of the head and eyes in one direction with neck extension.
They have a highly lateralizing value to the contralateral hemisphere.
What are versive seizures?
Seizures characterized by a direction with neck extension resulting in a sustained unnatural position, often indicating frontal lobe origin.
Versive seizures can be the first sign of frontal lobe seizures and have a high lateralizing value to the contralateral hemisphere.
How do hypermotor seizures manifest?
They consist of complex movements involving trunk and proximal segments of limbs, resembling normal movements.
These seizures occur mostly during sleep and may involve large movements such as pedaling or running.
What distinguishes automotor seizures?
Automatisms involving distal segments of the hands, feet, mouth, and tongue, typically associated with temporal lobe epilepsy.
Frontal lobe automotor seizures are usually shorter in duration.
What are gelastic seizures?
Seizures characterized by laughing as the main motor manifestation.
Approximately 50% of cases are associated with hypothalamic hamartomas detectable by MRI.
Define atonic seizures.
Seizures resulting in loss of postural tone, leading to falls or head drops, most common in symptomatic generalized epilepsies.
Atonic seizures can also occur in focal epilepsies but are typically associated with slower falls.
What characterizes hypomotor seizures?
A decrease or total absence of motor activity, noted in patients whose consciousness cannot be tested.
Common in temporal and parietal lobe epilepsy.
What are akinetic seizures?
Seizures characterized by the inability to perform voluntary movements despite the patient being conscious.
They arise from activation of negative motor areas in the mesial frontal and inferior frontal gyri.
What occurs during aphasic seizures?
The patient is aphasic despite preserved awareness and memory, often lateralizing epilepsy to the dominant hemisphere.
These can present as status epilepticus.
What is dystonic posturing?
A sustained, forced, unnatural positioning of an upper extremity on one side, often indicating lateralization to the contralateral hemisphere.
Common in temporal lobe epilepsy, linked to basal ganglia activation.
What is ictal speech?
The presence of intelligible speech during unresponsiveness and/or distal automatisms, often lateralizing to the non-dominant hemisphere.
This sign has limited reliability due to exceptions.
What does post-ictal aphasia indicate?
Lateralizes epilepsy to the language dominant hemisphere, especially in temporal lobe epilepsy.
Recovery of language function is often delayed in left temporal lobe epilepsy.
What is Todd’s paralysis?
A non-localizing but lateralizing sign that follows prominent ipsilateral motor activity of the affected limb.
It indicates prior seizure activity in the affected hemisphere.
What does post-ictal nose wipe signify?
Lateralizes the epilepsy to the ipsilateral hemisphere in temporal lobe epilepsy.
It suggests post-ictal neglect in the contralateral hemisphere.
What is the significance of unilateral eye blinking during seizures?
It is a lateralizing sign to the ipsilateral hemisphere but has no localizing value.
The mechanism behind this phenomenon remains unclear.
What is ictal nystagmus?
A predominantly horizontal nystagmus with the fast phase opposite the seizure focus, often associated with ictal vertigo.
This can originate from the occipital or temporo-occipital junction.
What are the limitations of seizure semiology as a localizing tool?
Subjectivity, inter-rater variability, and inability to always differentiate focal or generalized epilepsies.
Focal signs can occur in generalized epilepsy and vice versa.
What is the conclusion regarding seizure semiology?
It is a useful tool but requires standardization among evaluators to avoid conflicting signs.
Consensus among qualified observers is crucial for accurate interpretation.
What is the role of the Frontal Lobe in bilateral tonic posture?
Involved in bilateral tonic posture
Frontal Lobe is responsible for motor functions and postural control.
Which area of the brain is associated with the Supplementary Motor Cortex?
Frontal Lobe
The Supplementary Motor Cortex is crucial for planning and coordinating movements.
What type of movements are associated with the Frontal Lobe?
Simple Movements such as limb twitch and Jacksonian march
Jacksonian march refers to the sequential spread of motor activity in a limb.
What is the contralateral function of the Frontal Lobe?
Controls movements on the opposite side of the body
This means that damage to one side of the Frontal Lobe can affect the opposite side’s motor functions.
What abnormal sensation is linked to the Insula?
Abnormal Taste Sensation (Dysgeusia)
Dysgeusia refers to a distortion of the sense of taste.
Which brain region is associated with visceral or autonomic abnormalities?
Insular-Orbital Frontal Cortex
This region plays a role in autonomic functions and emotional responses.
What type of hallucinations are associated with the Anteriomedial Temporal Lobe?
Olfactory Hallucinations
Olfactory hallucinations involve perceiving smells that are not present.
Which functions are affected by the Amygdala?
Chewing, Salivation, Speech Arrest
The Amygdala is involved in emotional responses and autonomic functions related to these behaviors.
What complex behaviors are associated with the Temporal Lobe?
Complex Autonomic Behaviors
These behaviors include emotional and sensory processing.
What kind of visual hallucinations can occur in the Posterior Temporal Lobe or Amygdala-Hippocampus?
Visual Hallucinations (Formed Images)
Formed images are detailed and recognizable visual perceptions.
What localized sensory disturbances are linked to the Parietal Lobe?
Tingling or numbness of the limb or half body
These disturbances can indicate sensory cortex involvement.
What type of visual hallucinations are associated with the Occipital Lobe?
Visual Hallucinations (Unformed Images, flashing, patterns)
Unformed images are less recognizable and may include lights or patterns.
What is the ictal onset location for bilateral tonic posturing?
Supplementary motor cortex
This indicates the area of the brain involved during the seizure activity.
Where does ictal onset occur for limb twitching?
Contralateral frontal lobe
This suggests that the twitching is controlled by the opposite side of the brain.
What does head or eye deviation to one side indicate about ictal onset?
Ictal onset is ipsilateral to head turn (Mid-posterior temporal lobe)
This shows the correlation between head movement and seizure activity.
What type of seizure is indicated by bicycling movements?
Frontal lobe seizure
This refers to specific motor activities associated with frontal lobe seizures.
What does dystonic posturing of the arm indicate about ictal onset?
Ictal onset is contralateral, may indicate a temporal lobe seizure
Dystonia can suggest involvement of temporal lobe functions.
What is the ictal onset for tonic posturing?
Ictal onset is contralateral
This means the posturing affects the opposite side of the body.
What does the figure 4 sign indicate about ictal onset?
Ictal onset is contralateral to the extended arm
The figure 4 sign can be an indicator of specific seizure types.
What does unilateral hand automatisms indicate about ictal onset?
Ictal onset is ipsilateral
This shows that automatic movements occur on the same side as the seizure focus.
What does postictal nose wiping indicate about ictal onset?
Ictal onset is ipsilateral to the wiping hand
This reflects the side of the body affected during the seizure.
What is the ictal onset for unilateral eye blinking?
Ictal onset is ipsilateral
This means the blinking occurs on the same side as the seizure activity.
Where does abnormal taste originate during a seizure?
In the insula
The insula is involved in processing taste sensations.
What does the presence of visceral symptoms (e.g., vomiting) indicate about ictal onset?
Ictal onset in the insular-orbital frontal cortex
This indicates the involvement of specific brain regions in autonomic responses.
Where does ictal onset for olfactory hallucinations occur?
In the anterior medial temporal lobe
This area is associated with processing smells.
What does chewing and salivating during a seizure indicate about ictal onset?
Ictal onset in the amygdala
The amygdala plays a role in emotional and autonomic responses.
What type of behavior is associated with ictal onset in the mesial temporal lobe?
Complex autonomic behaviorisms
This reflects the integration of emotional and autonomic functions.
Where does ictal onset for visual hallucinations occur?
In the posterior temporal lobe, amygdala-hippocampus, or occipital lobe
These areas are crucial for visual processing.
Where is the ictal onset for localized sensory disturbances?
In the parietal lobe
The parietal lobe is responsible for processing sensory information.
True or False: Anterior tongue bites are common in non-epileptic events.
True
This contrasts with lateral tongue bites, which are more typical in seizures.
What is ictal weeping associated with?
Can occur in temporal lobe seizures or psychogenic seizures
Ictal weeping is a rare phenomenon that can indicate seizure type.
What does semiology in focal epilepsies reflect?
Activation/dysfunction of areas of the brain termed the symptomatogenic zone
This reflects how seizures begin and evolve.
What is the symptomatogenic zone?
The area where symptoms and clinical signs originate, usually close to the epileptogenic zone
What is the difference between the symptomatogenic zone and the epileptogenic zone?
The symptomatogenic zone is where symptoms originate, while the epileptogenic zone is the part of the brain that must be removed to render the patient seizure-free
How fast does the ictal wavefront move during seizure propagation?
About 1 mm/s
What is the speed of faster ictal discharge during seizure propagation?
About 300 mm/s
What is the Jacksonian march?
A pattern of seizure activity reflecting ictal activity spread through the motor cortex along the homunculus
True or False: Frontal lobe seizures are typically brief and may cluster.
True
What are common motor features of frontal lobe seizures?
Simple clonic movements, tonic posturing, eye deviation, cycling, rocking, and grimacing
Seizures can appear bizarre, with bilateral motor phenomena.
What can make frontal lobe seizure semiologies complex and hard to interpret?
High connectivity with other cortical regions leading to disinhibition rather than direct activation
What are the characteristics of seizures from the primary motor cortex?
Contralateral unilateral clonic or sometimes tonic or myoclonic activity
What defines supplementary motor area seizures?
Asymmetric bilateral tonic posturing, with or without impaired awareness
Fill in the blank: Frontal lobe seizures may cause _______ symptoms.
Clonic movements
What are common features of temporal lobe seizures?
Behavioral arrest, manual and oral automatisms, variable degrees of loss of awareness, postictal confusion
How can focal impaired awareness seizures be distinguished from absence seizures?
Focal impaired awareness seizures are longer, may be preceded by aura, and are commonly associated with automatisms
What do auras in temporal lobe epilepsy commonly include?
Abdominal aura, experiential phenomena such as fear, déjà vu, and jamais vu
What is the most frequent site of origin for focal seizures?
Temporal lobe
What symptoms can arise from parietal lobe seizures?
Contralateral somatosensory aura, vertiginous aura, distortion of body image or visual perception
What is a common characteristic of occipital lobe seizures?
Visual aura or oculomotor features such as eye deviation, blinking, or nystagmus
What is the ictal pout sign or ‘chapeau de gendarme’?
Characterized by a downturned mouth from bilateral lip and chin contraction
What are reflex seizures?
Seizures triggered by specific stimuli
What is the most common reflex epilepsy?
Photosensitive epilepsy
True or False: Gelastic seizures typically arise from hypothalamic hamartomas.
True
What is a common symptom of seizures arising from the anterior cingulate?
Intense fright, screaming, and vocalizations
What are some lateralizing signs in seizures?
Unilateral clonic movements, unilateral tonic or dystonic posturing, early head version
What is the primary visual cortex responsible for in occipital lobe seizures?
Causes an elementary visual aura, typically brief and lateralized
What are the characteristics of Simple Partial Seizures?
Duration 5-10 sec, no loss of awareness, no postictal confusion, ictal EEG shows focal spikes
Commonly involves the face, hands, or half of the body.
What does bilateral tonic posture indicate in seizure classification?
Frontal lobe (supplementary motor cortex) dysfunction
This is one of the manifestations of partial seizures.
What is the site of dysfunction associated with olfactory hallucinations?
Anteromedial temporal lobe
This can occur during partial seizures.
What are the characteristics of Complex Partial Seizures?
Usual duration variable, 5-10 sec to 1-2 min, loss of awareness, focal or lateralizing
These seizures can vary significantly in duration.
What is the duration and characteristics of Absence seizures?
5-10 seconds, clustering, loss of consciousness, no postictal confusion
Characterized by generalized 3Hz spike and wave on EEG.
At what age does Absence seizure onset typically occur?
Onset 3-12 years; Peak 6-7 years
Often associated with normal intellect.
What is Status Epilepticus?
A medical emergency characterized by prolonged seizures
It requires immediate intervention to prevent complications.
