Episodic Neurological Disturbances of Nonepileptic Origin	169

Treatment. Grand mal status epilepticus should be treated with a bolus dose of a benzodiazepine, e. g., diazepam 10−20 mg i. v., followed by intravenous phenytoin (by slow push or drip) or valproate (IV push followed by drip). If seizure activity does not stop within

40 minutes, the patient must be intubated and ventilated and put in artificial coma with a barbiturate such as thiopental or propofol.

Petit mal status epilepticus and psychomotor status epilepticus respond to clonazepam 2−4 mg i. v.

Episodic Neurological Disturbances of Nonepileptic Origin

Because the clinical presentations of epileptic seizures are so highly varied, their differential diagnosis necessarily includes a wide variety of conditions. Any episodic loss of consciousness, impaired motor function, or fall might be due either to an epileptic seizure or to a nonepileptic event of another etiology, as will be discussed in this section.

Episodic neurological disturbances of nonepileptic origin can be classified into four major types, as follows:transient loss of consciousness and falling;

falling without loss of consciousness;

loss of consciousness without falling; and

episodic movement disorders without loss of consciousness.

Episodic Disturbances with Transient Loss of Consciousness and Falling

Table 9.9 provides a quick overview of nonepileptic disturbances of this type (and, for completeness, also includes some that are of epileptic origin). Only the more important ones are described in greater detail in this section.

Table 9.9 Clinical features of various conditions causing brief loss of consciousness and falls

“Falling sicknesses”	Found in:	Precipitating factors	Prodromal phenomena

Syncopal attacks

orthostatic hypotension (vasomotor collapse)

chronic sympathetic autonomic Shy−Drager, tabes dorsalis failure

	medications		diuretics, antihypertensives,
		-blockers/L-Dopa
	adolescents		possibly due to anemia
	reflex circulatory syncope (vagal inhibition)
	vagovasal syncope		hyperventilation
			heat, fright, etc.
	swallowing syncope		glossopharyngeal neuralgia
	carotid sinus syndrome		elderly men
	pressor syncope (inadequate venous return)
	coughing/laughing syncope		persons with emphysema

prolongued standing; rapidly

standing up from a lying position

intense emotion pain

paroxysms

carotid pressure

coughing fit laughing fit

micturition syncope		men, alcohol		urination while standing
“extension syncope”/squatting		children, possibly on purpose		hyperextension
				squatting and pressing!
primary cardiovascular syncope
cervicobrachial stenosis		subclavian steal syndrome		physical
		aortic arch syndrome		exertion
		e. g., subaortic stenosis		(arm)
cardiac anomalies/heart failure
“sinoatrial syncope”		cardiac arrhythmias		sometimes induced by
				intense emotion

yawning, tinnitus, feeling of heat, epigastric pressure

fright, anxiety

	Adams−Stokes attack		grade III A−V block		independent of position	often without warning
	respiratory affect seizure
	cyanotic affect seizure		infants		anger/spite
			school-aged children		fright
	“white” affect seizure			pain
						Continued
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Epilepsy and Its Differential Diagnosis

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170 9 Epilepsy and Its Differential Diagnosis

Table 9.9 Clinical features of various conditions causing brief loss of consciousness and falls (Continued)

“Falling sicknesses”	Found in:	Precipitating factors	Prodromal phenomena

falling attacks

true reflex “vestibular” syncope	Ménière disease	head movements (sometimes)	dizziness (sometimes)
(Tumarkin syndrome)	paroxysmal positioning		vertigo
	vertigo
intermittent vertebrobasilar	elderly patients	head turning (sometimes)	nausea, dizziness
ischemia	vascular risk factors		visual disturbances, etc.
cryptogenic falling attacks in	middle-aged women	only while walking	no prodromal
women			phenomena
cataplectic falling	isolated, or in the setting of	intense emotion	without warning
	narcolepsy	laughing
		fright

epilepsy

“temporal lobe syncope”	psychomotor epilepsy	intense emotion (sometimes)	psychomotor aura
			possible
grand mal seizure	possibly several times/day	sleep deprivation	aura possible
	any age	alcohol
drop attacks (myoclonic−astatic)	Lennox−Gastaut syndrome
	(children)

psychogenic

hysterical falling (with impairment	neurotic disorders
of consciousness)	psychological gain
simulated falling attacks/seizures	may occur in patients who also	attacks occur only before an
	have true epileptic seizures	“audience”
	malingering (“compensation
	neurosis”)

Syncope

Syncope is a very brief loss of consciousness during which the affected individual falls to the ground. It is due to a very brief loss of function of the brainstem reticular formation, which, in turn, is usually caused by temporary ischemia and tissue hypoxia. Syncope can be of vasomotor or cardiogenic origin.

Reflex circulatory syncope, the commonest kind of syncope, can be precipitated by intense emotion (e. g., the sight of blood, anticipatory anxiety), heat, prolonged standing, or physical pain. The affected person becomes dizzy, sees black spots before his or her eyes, turns pale, breaks out in a sweat, and then collapses to the ground. Wakefulness and full orientation are regained at once in most patients.

Etiologic subtypes of reflex circulatory syncope include idiopathic vasomotor collapse in adolescents, pressor syncope after prolonged coughing, micturition syncope, swallowing syncope, and extension syncope (mainly seen in younger patients who stand up too quickly from a squatting position). Orthostatic syncope is a feature of many neurological diseases (e. g., multisystem atrophy).

Carotid sinus syncope is rarer than once thought. Vestibular syncope occurs, e. g., in acute paroxysmal positioning vertigo.

Cardiogenic syncope is especially common in older patients. Its causes include cardiac arrhythmias (thirddegree AV block, sick sinus syndrome, tachycardias) and

other types of heart disease (e. g., valvular aortic stenosis, atrial myxoma, and chronic pulmonary hypertension with cor pulmonale).

“Convulsive syncope”: syncopal episodes are sometimes accompanied by brief, clonic muscle twitching. This may make a syncopal episode even harder to distinguish from an epileptic seizure.

Episodic Falling without

Loss of Consciousness

Drop Attacks

In a so-called drop attack, the patient suddenly falls to the ground without braking the fall. Consciousness is apparently preserved during the event; in some patients, however, the patient may, in fact, lose consciousness without realizing it afterward, and too briefly for others to observe. Some drop attacks are due to atonic epilepsy, others to basilar ischemia. Cryptogenic drop attacks have been described in older women (“climacteric drop syncope”). Finally, drop attacks can be caused by basilar impression and other structural abnormalities of the craniocervical junction.

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Episodic Neurological Disturbances of Nonepileptic Origin	171

Table 9.10 Distinguishing features of the narcolepsy−cataplexy and sleep apnea syndromes

Aspect Narcolepsy−cataplexy Sleep apnea

History	30−50 % positive family history, onset usually in 2nd or 3rd
	decade of life
Daytime sleep	usually in sleep-promoting situations, patient feels rested af-
	terward; there are also hypovigilant twilight states
Nighttime sleep	often restless, nightmares, sometimes sleep paralysis,
	patients sometimes do not feel rested in the morning, no
	headache

negative family history, onset usually in middle or old age

overwhelming need to sleep; patient does not feel rested afterward

loud snoring, respiratory pauses lasting more than 10 seconds (hallmark), diminished O2 saturation of the blood, sometimes angina pectoris during sleep, patients usually do not feel rested in the morning, headache

Other features	cataplectic states, e. g., loss of affective tone, hypnagogic	no cataplexy, sometimes hypnagogic hallucina-
	hallucinations and automatic behavior, no dementia	tions and automatic behavior, perhaps (reversi-
		ble) dementia
Clinical findings	sometimes short, stocky habitus	usually men, almost always obese, often hyper-
		tensive, occasional anomaly of nasopharynx
Ancillary tests:
EEG	often signs of somnolence, short sleep latency, early REM	unremarkable
Other	sleep, frequent alternation with nonREM sleep
	HLA-DR2 constellation	no specific HLA type

Cataplexy

Cataplexy, a component of the narcolepsy−cataplexy syndrome, may present with the clinical picture of an unexplained, atonic fall. Directed history taking then reveals some or all of the five cardinal symptoms of cataplexy:

disturbance of wakefulness, usually with brief and restorative naps during the day (in sleep-promoting situations);

falls, due to sudden loss of muscle tone, precipitated by fright or other emotions (affective loss of muscle tone), and perhaps brief local loss of tone in individual muscle groups;

disturbance of nighttime sleep, with nightmares;

sleep paralysis, i. e., brief inability to move on awakening;

partial hypovigilance states and hallucinatory experiences, mostly while falling asleep (hypnagogic hallucinations).

The diagnosis of this disorder, which tends to occur in families, is made on clinical grounds and confirmed by the following objective findings:

HLA-DR2 constellation and characteristic EEG abnormalities (SOREM = sleep-onset REM = early REM sleep stages);

frequent somnolence;

the appearance of REM sleep during the first hour of nighttime sleep, and

frequent alternation of REM sleep with typical, deep sleep (Fig. 9.6).

Important clinical aspects of the differential diagnosis of the narcolepsy−cataplexy syndrome—in particular, its distinction from sleep apnea syndrome—are listed in Table 9.10.

Differential diagnosis: sleep apnea syndrome. This syndrome mainly affects middle-aged and elderly men

who snore loudly. Typical manifestations, other than snoring are motor unrest during sleep and repeated respiratory pauses due to airway displacement. When one of these pauses occurs, the patient becomes half awake, with a start, before beginning to breathe again. The repeated pauses interfere considerably with sleep. The patient awakens the next day feeling poorly rested, often complaining of headache; the next day, he or she is tired, falls asleep repeatedly, and may suffer from impaired intellectual performance or even (reversible) dementia. The diagnosis is established by polysomnography. Treatment with continuous positive-pressure respiration, through a mask, during nighttime sleep often results in dramatic improvement.

Episodic Loss of Consciousness without Falling

Certain metabolic disturbances (e. g., hypoglycemia) and electrolyte disturbances (particularly hyponatremia), as well as endocrine diseases (hypothyroidism, hypoparathyroidism), can cause episodic loss of consciousness. Unconsciousness can also be the most prominent manifestation of tetany, e. g., in hyperventilation; other signs include Chvostek sign, paresthesiae of the fingers and mouth, and tonic muscle contractions, with carpopedal spasm.

Episodic Movement Disorders without Loss of Consciousness

The following nonepileptic movement disorders must be distinguished from focal motor epilepsy:

Focal, repetitive twitching of various types: hemifacial spasm is a synchronous involuntary contraction, at irregular intervals, of muscles innervated by the facial nerve on one side of the face. Tics and

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Epilepsy and Its Differential Diagnosis

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172 9 Epilepsy and Its Differential Diagnosis

Normal sleep profile

Depth of sleep

REM = paradoxical sleep

awake

sleep stages I–IV

REM

Sleep profile in narcolepsy–cataplexy syndrome

initial REM sleep	frequent awakening
awake
sleep
stages I–IV

REM

time

0

60

120

180

240

300

min.

Fig. 9.6 Sleep profile in the narcolepsy−cataplexy syndrome (below) compared to a normal sleep profile (above).

blepharospasm are usually bilateral. Palatal nystagmus is due to a lesion of the olive or the central tegmental tract. Myoclonus and myorrhythmia are usually not confined to a particular muscle or muscle group, but tend to migrate from one to another.

Episodic, generalized motor processes include paroxysmal choreoathetosis, which may be familial or due to multiple sclerosis, and tonic brainstem seizures, which are likewise a feature of MS (p. 158).

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