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Questions and Answers
What percentage of patients with LPDs have no structural abnormality on neuroimaging?
What percentage of patients with LPDs have no structural abnormality on neuroimaging?
What type of seizure is most commonly associated with LPDs?
What type of seizure is most commonly associated with LPDs?
In the study involving 82 patients with LPDs, what percentage had clinical seizures?
In the study involving 82 patients with LPDs, what percentage had clinical seizures?
What was the percentage of patients with seizures who also had LPDs according to Claassen et al.'s findings?
What was the percentage of patients with seizures who also had LPDs according to Claassen et al.'s findings?
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Which condition was found to have seizures more commonly associated with LPDs?
Which condition was found to have seizures more commonly associated with LPDs?
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What is the typical frequency range for LPDs?
What is the typical frequency range for LPDs?
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Which of the following statement is true concerning the location of LPDs?
Which of the following statement is true concerning the location of LPDs?
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What is the typical morphology of LPDs as described?
What is the typical morphology of LPDs as described?
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In the context of EEG, how might the contralateral hemisphere respond to LPDs originating from one side?
In the context of EEG, how might the contralateral hemisphere respond to LPDs originating from one side?
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How does standardized ACNS terminology categorize LPDs?
How does standardized ACNS terminology categorize LPDs?
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What condition appears more often in patients with bilateral independent periodic discharges (BIPDs) compared to those with lateralized periodic discharges (LPDs)?
What condition appears more often in patients with bilateral independent periodic discharges (BIPDs) compared to those with lateralized periodic discharges (LPDs)?
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In the context of patients exhibiting BIPDs, what percentage of those with central nervous system infections experienced clinical or electrographic seizures?
In the context of patients exhibiting BIPDs, what percentage of those with central nervous system infections experienced clinical or electrographic seizures?
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What is one significant difference between the occurrence of seizures in patients with LPDs compared to those with BIPDs?
What is one significant difference between the occurrence of seizures in patients with LPDs compared to those with BIPDs?
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Which of the following conditions is more prevalent in patients with BIPDs than those with LPDs?
Which of the following conditions is more prevalent in patients with BIPDs than those with LPDs?
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Based on mortality rates, which group has shown a higher percentage of mortality when comparing BIPDs to LPDs?
Based on mortality rates, which group has shown a higher percentage of mortality when comparing BIPDs to LPDs?
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What key difference in functional outcomes has been observed between patients with BIPDs and LPDs?
What key difference in functional outcomes has been observed between patients with BIPDs and LPDs?
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Which type of periodic discharges is much less common than the other as per the studies discussed?
Which type of periodic discharges is much less common than the other as per the studies discussed?
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What is the reported likelihood of developing epilepsy in patients with LPDs?
What is the reported likelihood of developing epilepsy in patients with LPDs?
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What is the risk of posthospital seizures in ICU patients with LPDs and electrographic seizures?
What is the risk of posthospital seizures in ICU patients with LPDs and electrographic seizures?
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In the definition of LPDs plus (LPDs+), what types of activity are included?
In the definition of LPDs plus (LPDs+), what types of activity are included?
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What was the percentage of records that showed LPDs plus in the large series by Ruiz et al.?
What was the percentage of records that showed LPDs plus in the large series by Ruiz et al.?
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How does the presence of LPDs plus correlate with the likelihood of seizures compared to LPDs alone?
How does the presence of LPDs plus correlate with the likelihood of seizures compared to LPDs alone?
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What phenomenon is described by Hirsch et al. concerning patients with LPDs?
What phenomenon is described by Hirsch et al. concerning patients with LPDs?
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What was the outcome observed in patients with stimulus-induced LPDs (SI-LPDs) during their acute illness?
What was the outcome observed in patients with stimulus-induced LPDs (SI-LPDs) during their acute illness?
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What was noted about the presence of LPDs concerning patient outcomes compared to LPDs plus?
What was noted about the presence of LPDs concerning patient outcomes compared to LPDs plus?
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Study Notes
Lateralized Periodic Discharges (LPDs)
- LPDs are stereotyped, repetitive discharges.
- They occur regularly, mainly affecting one hemisphere.
- Often associated with herpes encephalitis, but more commonly ischemic stroke.
- Increased risk of seizures.
- Clinical significance and management are debated, especially in comatose patients.
- Considered part of the ictal-interictal continuum, potentially epileptogenic.
Epidemiology and Natural History of LPDs
- Frequency of LPDs on continuous EEG recordings ranges from 6.2% to 8.6%.
- In a study in India, LPDs were found in 47% of 99 neurological/neurosurgical ICU patients with altered sensorium.
- 22% of these patients had a clinical diagnosis of status epilepticus.
- Most common in patients with focal neurological deficits and altered consciousness.
Etiology of LPDs
- Frequently associated with acute structural cortical/subcortical lesions.
- Ischemic stroke is the most common cause in adults.
- Other causes include: viral/autoimmune encephalitis, brain tumors, intracranial hemorrhage, and anoxic encephalopathy.
- In children, infections are more common, along with stroke and hypoxic-ischemic encephalopathy.
- Other causes include Creutzfeldt-Jakob disease, subarachnoid hemorrhage, demyelinating diseases, posterior reversible encephalopathy syndrome (PRES), migraine, mitochondrial encephalopathy (MELAS), and progressive myoclonic epilepsies.
- Metabolic disturbances may play a role in LPDs genesis, but not always.
EEG Characteristics of LPDs
- Discrete, repetitive discharges with consistent morphology.
- Recurring at intervals between 0.5 and 3 Hz.
- Usually broadly lateralized to one hemisphere, but can be maximal in specific regions.
- EKG and pulse artifact should be distinguished during simultaneous recordings.
Association with Seizures
- Clinical seizures occur in a majority of LPD patients.
- Seizures often occur before or concurrently with LPD observation.
- Seizures are more common in LPDs associated with stroke/brain tumors compared to infection/other etiologies.
- Focal motor seizures are the most common seizure type associated with LPDs.
- Strong correlation between LPDs and nonconvulsive seizures on prolonged EEG.
- LPD frequency correlates with seizure risk; lower frequencies are associated with less risk.
Prognosis
- High mortality rate in LPD patients, ranging from 24% to 53%.
- Higher mortality in pediatric patients.
- Presence of clinical seizures associated with slightly better prognosis.
- LPDs are independent predictors of poor outcome in various patient populations (moderate-to-severe disability or death).
Bilateral Independent Periodic Discharges (BIPDs)
- Less common than LPDs.
- Asynchronous periodic discharges independently in both hemispheres.
- Similar etiologies to LPDs (e.g., strokes, infection, tumors).
- Coma is more commonly associated with BIPDs with less common seizure occurrence compared to LPDs.
- Higher mortality rate associated with BIPDs compared to LPDs.
LPD Subtypes (LPDs Plus)
- Includes superimposed rhythmic discharges (often low-voltage fast activity).
- Associated with higher likelihood of seizures compared to LPDs without the superimposed fast activity (LPDs+).
- Stimulus-induced LPDs or SI-LPDs are induced by external stimuli, but their exact pathophysiological significance remains unclear.
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Description
This quiz explores the characteristics, epidemiology, and etiology of Lateralized Periodic Discharges (LPDs). It highlights their significance in neurodiagnostic settings, particularly in patients with altered consciousness and their association with various neurological conditions. Assess your understanding of LPDs and their implications in clinical practice.
