Читать книгу Pediatric stroke. Revascularization and reconstructive surgery in children with cerebrovascular disease - E. V. Shevchenko - Страница 9

Clinical manifestations of acute cerebrovascular diseases in the carotid system of children are typical enough, and they reveal in a focal neurologic deficiency with developing motor disturbances (87—95%), disturbances of speech, sensibility and vision as well as other symptoms corresponding to the location of cerebral tissue lesions. In massive strokes during the acute period of the disease, as a rule, general neurological symptoms are more marked, which is caused by edema and dislocation of the brain. When the ischemic zone is small, the focal symptoms develop in the background of the generally normal state. The clinical picture of a cerebrovascular disease in a child may be atypical: nausea, vomit and depression of consciousness may be replaced with agitation or body temperature rise and convulsions (19—58%).

For obtaining more objective data on the severity of clinical manifestations of the ACVD and assessing the neurologic deficiency changes in acute and rehabilitation periods of the stroke, the PedNIHSS (Pediatric National Institute of Health Stroke Scale) scale is used, which has showed its consistence with the NIHSS scale [175; 235]. During the period of residual effects, American researchers apply the PSOM scale (Pediatric Stroke Outcome Measure) [37; 107]. These scales are rather extensive, but easy to fill in, so they can be automated and introduced into the patient examination standard. The obstacle for their implementation in the RF territory is the need for training of specialists in the estimation methodology proper as well as the need for validation of evaluation and measurement scales.

A paroxysmal syndrome often becomes the first symptom of any type of a CVD in children. More frequent registration of the paroxysmal syndrome is noted in the infant group [60; 69; 81; 291]. In children, the paroxysmal syndrome is typical not only for a stroke, but also for various brain damages (mass lesions, etc.). Due to its high diagnostic significance, it is recommended by the American Epilepsy Society as a mandatory indication for brain MRI [122].

The emergence of convulsions at the onset of a cerebrovascular pathology is a relatively unfavorable sign. It is proved that it is specifically the ACVD manifestation in paroxysms recurring soon, that is associated with the unfavorable prognosis regarding the patient rehabilitation and the restoration of the focal neurologic deficiency as well as with the risk of emergence and severe course of symptomatic epilepsy [99; 125; 259]. Normally, convulsions are not the only manifestation of an ACVD. A focal neurologic deficiency develops either alongside with them, or in the later periods [35; 220; 280]. The largest samplings of patients with an ACVD and formation of a post-stroke epilepsy during the subsequent period of the disease are presented in Table 1.

Table 1: Epilepsy formation risk in children, who had suffered an ischemic stroke (according to literature data from 2010 till 2015)

On the other hand, the first manifestations of the disease may be rather non-specific: an isolated degradation of consciousness level or a headache, which, considering age, difficulties in awareness and in verbalization of unusual symptoms by the child itself as well as lack of «stroke» alertness in pediatric neurologists, leads to an essential delay in neuroimaging and ACVD diagnosing [24; 60; 63; 67; 179]. These circumstances often lead to a rather paradoxical situation called «clinicodiagnostic scissors»: children with CVD symptoms are hospitalized promptly enough, but they do not get adequate verification of the diagnosis, including an instrumental one, and, therefore, they do not get the treatment.

Pediatric patients find themselves in a hospital, on the average, within the first three hours from the onset of the ACVD symptoms, but they get to the neuroradiologists within 8 hours, whereas for adult patients these deadlines are 8 and 2 hours respectively [63; 103; 179; 247]. Transient motor and/or sensorial disturbances in the structure of partial attacks lead to the initial diagnoses, which are most common in children (epilepsy, neuroinfection, crainio-cerebral injury, etc.) and which, therefore, occupy top positions in the immediate memory of emergency phase doctors [103; 247].

During the analysis of the clinical picture in children with IS, examined by specialists of the FSBEI of Higher Professional Education «Urals State Medical University», the following data on the varying occurrence of clinical symptoms were obtained in 162 children (Table 4). Within the first 24 hours of the disease the comparability was noted between the registration rates of general cerebral and focal neurological symptoms. During the acute period of the IS, the most typical combination of symptoms in children were the degradation of consciousness level and the central pareses of limbs and mimic muscles.

Practically, every fourth child at an age enabling the adequate assessment of these symptoms had signs of ataxia and speech disturbances. Thus, the most prominent combinations of symptoms, which form the diagnostic rules such as «Give me five»1 and FAST2 in stroke diagnostics at the age typical for IS and TIA, can also be successfully applied in pediatric practice.

The spectrum of focal neurologic symptoms in patients was consistent with the blood supply systems and the infarction location. In the hospital stay period, the neurologic deficiency persistence had a direct positive connection with the size of the stroke zone on CT or MRI (r=0.56, p <0.05).

The rate of admitting children with verified IS (n=158) and TIA (n=62) to the specialized care delivery stage was analyzed (Table 2).

Thus, only a little more than half of the children with IS get to the specialized care delivery stage within the reported deadlines accepted for hospitalization of adults – within the boundaries of the so called «time slot» (up to three hours) – 59% (n=93), when thrombolysis is possible. For children with TIA the onset of focal or general cerebral symptoms did not remain unnoticed also in more than a half of cases – 60% (n=37). On the other hand, a short-term and transient nature of symptoms in TIA have led to the lack of the emergency hospitalization and to scheduled health-seeking in 40% of children in this group (n=25).

Blood circulation diseases of the VBS have such typical symptoms as vertigo with nausea and vomit, disorder of static equilibrium and gait, ataxia in limbs and nystagmus, and such less typical symptoms as pareses in the limbs and various sensibility variations, lesions of cerebral nerves (CN) caused by a cerebrovascular disease in the brain stem. In ischemia of occipital lobes there may be some disturbances of visual functions [17].

Table 2: Time passed from the onset of the first ACVD symptoms till the admission to an emergency / neurology specialized healthcare facility

A chronic cerebrovascular ischemia most often manifests itself in signs of a dyscirculatory encephalopathy (DEP) characterized by diffuse-type headaches, vertigo, tinnitus, memory derangements, emotional lability, increased fatigability and performance impairment, sleep disorder. In DEP, general symptoms prevail without focal neurologic symptoms: severe headaches (77%), increased fatigability (68%), hypomnesia (44%) [17]. Decreased learning capacity is typical for such children.

Regarding the specific features of the clinical course of some types of the pathology, it should be mentioned that clinical manifestations of stenosis and occlusion of major cerebral vessels do not have any specific features and can manifest themselves as various ischemic cerebrovascular diseases. A moderate decrease of the cerebral blood flow usually does not manifest itself clinically (asymptomatic disease course), or it may be accompanied by some unspecific complaints.

At the onset of the moyamoya disease and syndrome, their clinical manifestations are rather diverse, and they may resemble the clinical manifestations of cerebrovascular disturbances in pathologic deformations of major cerebral vessels, thrombosis and atherosclerosis of intracranial arteries as well as the manifestations of other diseases (epilepsy, malformations of cerebral vessels, subarachnoid and intra-cerebral hemorrhages of various genesis [192; 196; 270].

Headache is mentioned as a manifesting symptom in a variety of studies on the moyamoya disease occurring in children too. In literature, there is even an individual notion – a headache associated with the moyamoya disease (HAMD) [141; 233; 238; 288]. Headache is often the only symptom at the onset of this disease. The headache is supposed to be caused by a compensatory dilatation of meningeal and leptomeningeal arteries, which can stimulate nociceptive receptors of dura mater of brain (DMB). The headache may have a migraine-like nature and be resistant to a drug therapy. However, this symptom usually is not considered as a fatal sign. In most patients, the headache regresses after the surgery [71; 136; 238].

The subsequent joining of transient focal neurologic symptoms is often considered by neurologists as a manifestation of sub- or de-compensation of residual organic background under the effect of school loads, intense sports activities, viral infections, vaccinations, etc. They are acknowledged as TIAs most often retrospectively, after the verification of the moyamoya disease. A short-term and transient nature of symptoms in children, often combined with the inability to describe their «unusual» complaints verbally, result in delayed help-seeking and late hospitalization. According to literature data, the delayed diagnosing is noted in all patients, and it may exceed two years. The moyamoya disease is usually identified only after the child has suffered a typical IS, which is followed by various neuroimaging examinations. Clinical manifestations in children with the moyamoya disease are distributed in the occurrence rate as follows: ischemic symptoms – 80% of cases (including strokes – 40% and transitory ischemic attacks – 41%) [21; 80; 224; 242; 254]; epilepsy – 5%, intracranial hemorrhages – 2.5%; other symptoms – 12.5% of cases (headache, motor disturbances, or combined symptoms) [72; 80; 224; 242; 254].