“The term “drop attack” is correctly used to describe a very specific and benign (apart from risk of injury) syndrome in middle-aged and elderly women who suddenly fall to their knees without loss of consciousness.12 However, in more recent years, the same words have been increasingly used for “falls,” “syncope,” and other misadventures. The latter clinical scenarios should be spelled out in the history, and the term “drop attack” reserved for its original meaning.”
https://www.sciencedirect.com/topics/medicine-and-dentistry/drop-attack#:~:text=The%20term%20%E2%80%9C,its%20original%20meaning.
“Drop Attacks
The term drop attack should be reserved for a sudden fall without impairment of consciousness. It implies a sudden dysfunction of truncal and leg muscle tone or sudden leg weakness. Without affecting consciousness, such attacks implicate lower brainstem or spinal cord structures where postural maintenance reflexes and control of the trunk and both legs are governed in a region compact enough to be affected by a single process.
In older patients, hypoperfusion and syncope or near-syncope are always important considerations when it is uncertain that consciousness has been maintained. Cardiac syncope can occur suddenly, with rapid recovery, and the loss of consciousness may be forgotten. Because of the high morbidity rate, it is very important not to mistake cardiac syncope for drop attacks.
With truly maintained consciousness, brainstem ischemia is a major consideration. Pontine ischemia that affects the corticospinal tracts bilaterally can cause a loss of tone with preserved consciousness. Compression of ventral brainstem structures by a mass or ectatic basilar artery can do the same. With severe vertebrobasilar or cervical spine disease, compression of one vertebral artery by head turning can be sufficient. Brainstem ischemia is more common in older patients, usually includes other signs of cranial nerve dysfunction or ataxia, and usually comes on gradually. Much more rarely, transient anterior cerebral ischemia can lead to bilateral leg weakness.
Just a bit caudally, foramen magnum mass lesions can compress the brainstem or upper spinal cord. Especially with prior rheumatoid arthritis or severe cervical spondylosis, neck movement may cause transient compression. This can be exacerbated by trauma. Often, the examination shows signs of a myelopathy. Rarely, mass lesions or midline, third ventricular cysts cause sudden obstruction of cerebrospinal fluid pathways and acute hydrocephalus, leading to drop attacks. Usually, headaches are suggestive.
Atonic seizures may be called drop attacks but include a loss of consciousness. They can be rapid and dangerous. Most are generalized or generalize rapidly from a frontal or other focus. More violent myoclonic seizures explain some falls. Most patients with atonic seizures also have other seizures, and many suffer from Lennox-Gastaut syndrome or other childhood epilepsies with several seizure types. Tonic seizures, often part of Lennox-Gastaut syndrome also, may cause falls by sudden rigid extension of the legs and trunk. Some seizures remain focal but include enough weakness or limb malfunction to cause falls. Seizures tend to be stereotyped, and most cause falls with a longer loss of consciousness. They are an unlikely explanation for isolated drop attacks without other clear seizure types, especially in adults. Occasionally, myoclonus or asterixis in the legs or trunk can be severe enough to cause drops.
Other than simply tripping, patients may fall because of imbalance. This may be caused by cerebral, cerebellar, vestibular, spinal cord, or peripheral nerve dysfunction. Weakness, as a result of myopathy, infarcts, or other deficits, and spasticity are possible causes, as is impaired sensation (particularly somesthetic, although impaired vision and hearing can contribute). Parkinson’s disease and other basal ganglia disorders often impair postural reflexes. The falls may be transient, but basal ganglia disease, myelopathy, and peripheral neuropathy should be evident on neurologic examination. Patients with vestibular disease severe enough to cause imbalance and falls often have vertigo. Sudden, nearly violent vestibular dysfunction and imbalance may occur in Ménière’s disease; this should include sensorineural hearing loss and tinnitus along with vertigo and generally occurs in older patients. Medications are always a concern and may exacerbate prior neurologic illness. Nonneurologic diseases such as arthritis and orthopedic problems can also prompt falls.
A few authors have described a curious entity of isolated falls occurring during walking, often recurringg a few times a year, in women over age 40 with no leg weakness, myelopathy, basal ganglia disorder, or other identifiable cause. The legs seem to give out suddenly. Some events are prompted by pregnancy, suggesting a hormonal influence, although the cause is unclear.
Finally, cataplexy may be the purest form of drop attack, with a perfectly maintained consciousness and sudden atonia, often precipitated by a sudden emotional stimulus such as fear or laughter. Respiration and eye movements are maintained. Patients may remain atonic for several minutes. In many patients, cataplexy may take the form of a brief head nod or drop rather than a complete fall. Cataplexy appears to represent the atonia of rapid eye movement (REM) sleep occurring in waking. The abnormalities in tone at inappropriate times with regard to sleep, as well as the abnormal dreaming or hallucinations in wakefulness, indicate abnormalities in upper brainstem structures that control the onset of dreaming and atonia. At least some cataplexy is found in most patients with narcolepsy, and almost all cataplexy is part of narcolepsy. Less often, it may occur with other brainstem lesions or masses at the base of the skull.
Evaluation of drop attacks begins with a history, which seeks to determine whether syncope, especially cardiac, or seizures were actually involved. Prior cardiac disease, palpitations, TIAs, headache, hearing loss, vertigo, any sensory loss (including visual and auditory), or symptoms of narcolepsy are of interest. Medication history is always pertinent. The exact onset of the fall and the progression are important, and witnesses are valuable. The examination looks for raised intracranial pressure, evidence of old cerebrovascular disease, basal ganglia disorders with alterations in tone or movement, signs of a myelopathy (including spasticity), ataxia, and a search for weakness, especially in the legs.
With such varied causes, drop attacks can have no single therapy. One must treat the underlying cause, and anticoagulation for presumed TIAs or anticonvulsants for possible seizures are inappropriate without a reasonable diagnosis.
نوبات السقوط
يجب حجز مصطلح نوبة السقوط للسقوط المفاجئ دون إعاقة الوعي. وهو يشير إلى خلل مفاجئ في قوة عضلات الجذع والساق أو ضعف مفاجئ في الساق. دون التأثير على الوعي، تتضمن مثل هذه النوبات هياكل جذع الدماغ السفلي أو النخاع الشوكي حيث يتم التحكم في ردود أفعال الحفاظ على الوضعية والتحكم في الجذع وكلا الساقين في منطقة مضغوطة بما يكفي للتأثر بعملية واحدة.
في المرضى الأكبر سنًا، يكون نقص التروية والإغماء أو شبه الإغماء دائمًا من الاعتبارات المهمة عندما يكون من غير المؤكد أن الوعي قد تم الحفاظ عليه. يمكن أن يحدث الإغماء القلبي فجأة، مع التعافي السريع، وقد يُنسى فقدان الوعي. نظرًا لمعدل الإصابة المرتفع، من المهم جدًا عدم الخلط بين الإغماء القلبي ونوبات السقوط.
مع الحفاظ على الوعي حقًا، يعد نقص تروية جذع الدماغ اعتبارًا رئيسيًا. يمكن أن يتسبب نقص تروية الجسر الذي يؤثر على المسالك القشرية الشوكية على كلا الجانبين في فقدان التوتر مع الحفاظ على الوعي. يمكن أن يؤدي ضغط هياكل جذع الدماغ البطنية بواسطة كتلة أو شريان قاعدي متوسع إلى نفس الشيء. في حالة مرض فقري قاعدي أو مرض العمود الفقري العنقي الشديد، يمكن أن يكون ضغط أحد الشرايين الفقرية عن طريق تحريك الرأس كافيًا. يُعد نقص تروية جذع الدماغ أكثر شيوعًا عند المرضى الأكبر سنًا، وعادةً ما يتضمن علامات أخرى لخلل في الأعصاب القحفية أو ترنح، وعادةً ما يحدث تدريجيًا. وفي حالات نادرة جدًا، يمكن أن يؤدي نقص تروية الدماغ الأمامي العابر إلى ضعف ثنائي في الساق.
يمكن أن تضغط آفات كتلة الثقبة العظمى قليلاً في الذيل على جذع الدماغ أو النخاع الشوكي العلوي. وخاصةً مع التهاب المفاصل الروماتويدي السابق أو التهاب الفقرات العنقية الشديد، قد تسبب حركة الرقبة ضغطًا عابرًا.