Article Type : Review Article
Authors : Shunmugavelu K
Keywords : Trigeminal Neurinoma, Acoustic Neurinoma, and Olfactory Neuroblastoma
The term
“neurologic disorder” applies to any condition that is caused by a dysfunction
in part of the brain or nervous system, resulting in physical and/or
psychological symptoms. Cause of neurogenic disorder may be congenital,
perinatal or acquired.
The term
“neurologic disorder” applies to any condition that is caused by a dysfunction
in part of the brain or nervous system, resulting in physical and/or
psychological symptoms. Cause of neurogenic disorder may be congenital,
perinatal or acquired.
Neurocutaneous syndromes
(phakomatosis) include four important diseases: Sturge-Weber syndrome, tuberous
sclerosis, neurofibromatosis of Von Recklinghausen and incontinentia pigmenti.
Their specific importance is that of direct relationship to oral cavity and
facial structures. Gross head and neck anomalies are rare and Crouzon and
Apertz syndrome are two important syndromes of these anomalies having more
incidence and neural- oral manifestations. Neoplasia of orofacial region
include i) Neoplasias of orofacial nerves and their sheaths (e.g. neurofibroma,
neurolemmoma, traumatic neuroma, malignant schwannoma), ii) cranial nerve
tumors with orofacial affections (e.g. Trigeminal Neurinoma, Acoustic
Neurinoma, and Olfactory Neuroblastoma), and iii) systemic tumors with
significant neural and orofacial symptoms (e.g. Gardner syndrome and multiple
endocrine neoplasia). Disorders of Cranial nerves V, VII, IX, X and XII are
important for a dentist, because all sensory and motor functions in the
orofacial region are under the control of these nerves [1].
Most common neurological
disorders affecting children with orofacial manifestations include cerebral
palsy, epilepsy, cerebro-vascular accident/stroke, multiple sclerosis,
Guillain-Barre syndrome etc. A comprehensive
study of common neurological disorders and their manifestations are illustrated
below.
Cerebral
palsy (CP) is a common pediatric disorder occurring in approximately 2-2.5 per
1000 live births. It is a chronic motor disorder resulting from a
non-progressive (static) insult to the developing brain. The motor disorders
associated with CP are often accompanied by disturbances in coordination,
cognition, communication, and seizure disorders.
Children
with CP are at increased risk of developing dental problems from multiple
factors including motor and coordination difficulties, as well as limited oral
care and hygiene. In addition, approximately 30% of CP patients are
undernourished, affecting their dental health. The leading cause of poor
nutrition appears to be pseudo-bulbar palsy, affecting the coordination of sucking,
chewing, and swallowing. Excessive drooling (sialorrhea) also results from
pseudo-bulbar palsy, however, it may also be related to increased production of
saliva secondary to an irritating oral lesion, such as dental caries or
infection. In addition, gastroesophageal reflux disease (GERD) is another
common problem in children with CP causing regurgitation, vomiting, and
possible aspiration. The GERD affects the dental health and results in dental
erosions. Gingival
hyperplasia may be caused by the use of
antiepileptic drugs, particularly phenytoin. Drooling of saliva (sialorrhea)
appears to be the consequence of a dysfunction in the coordination of
swallowing mechanisms (pseudo-bulbar palsy) and mouth opening. Management of
this difficult problem is not very effective and includes a trial of an
anticholinergic medication, such as Glycopyrrolate and Scopolamine. Bruxism,
the habitual grinding of teeth, is a common problem in children with CP,
particularly those with severe motor and cognitive deficits. Bruxism may
lead to teeth abrasion and flattening of biting surface.
Children
with CP may be difficult to handle and uncooperative during dental assessment
and management. Sedation and anesthesia are frequently needed in such
situations, particularly if invasive procedures are needed. History of
respiratory difficulties and seizures represent a particular challenge to
induce sedation and anesthesia [2].
A stroke happens when the
blood supply to part of the brain is cut off. There are two main types of
stroke. Ischemic strokes are caused by a blockage in the blood supply to the
brain. Hemorrhagic strokes occur when blood leaks from a burst blood vessel
into the brain. Children aged from 28 days old to 18 years may experience weakness
or paralysis on one side of the body, facial drooping, speech problems and
headaches. These symptoms are most commonly associated with ischemic strokes.
Symptoms for hemorrhagic strokes can be vomiting, seizures and occasional
headaches. Whilst stroke classically presents
with an acute focal neurological deficit such as hemiplegia, speech or gait
disturbance, the presentation is highly dependent on the age of the child and
may not be specific. The younger the child, more non-specific for their
symptoms. Neonates usually present with seizures and symptoms of encephalopathy
(irritability, lethargy, excessive sleeps, or poor feeding) or
apnea. Toddlers can also present with nonspecific symptoms such as
increased crying, drowsiness, irritability, poor feeding, vomiting and
sepsis-like features.
The aim
of clinical and imaging triage is to differentiate ischemic, hemorrhagic and
non-vascular etiologies, triggering different management cascades. Diagnostic methods are MRI brain,
non-contrast CT scan. Lab investigations include complete blood count,
urinalysis, coagulation profile and when indicated blood culture, ECG and
lumbar puncture. Management of acute stroke includes medical therapy to reduce
bleeding or thromboembolic occlusion. 2. Thrombolysis with intravenous tissue
plasminogen activator (TPA) from 3-4.5 hours after stroke onset [3].
Following stroke patients
may experience oral problems like masticatory and facial muscle paralysis,
impaired taste sensation, diminished gag reflex and dysphagia. Maintenance of
oral hygiene, replacement of missing teeth should be done. Patients with a
history of stroke are usually using aspirin and warfarin, hence use of NSAIDs
may increase the risk of bleeding and their long-term use may reduce the
protective effect of aspirin. Stress reduction during dental visits should be
done for which preoperative inhalation N2O-O2 or oral
anxiolytic can be used. Local anesthesia containing epinephrine can be used in
stroke patients but should be used judiciously [4].
It is a relapsing
remitting autoimmune inflammatory demyelinating disease of the CNS. It can be
caused secondary to trauma. Though the exact cause of M.S. is unknown, genetic
susceptibility clearly exists. It is mostly an autoimmune reaction in which
major histocompatibility complex (MHC) on chromosome 6p21 has been identified.
Infections agents like Epstein Barr virus and human herpes virus 6 are also
implicated in the pathogenesis of M.S. The sudden onset of optic neuritis
without any other CNS signs or symptoms could be the first symptom of MS.
Diplopia, blurring, nystagmus is also commonly seen. Limb weakness is
characteristic of MS and can be manifest as loss of strength, fatigue or gait
problems. Ataxia may affect the head and neck of MS patients and may cause
cerebellar dysarthria. These patients often show sensory impairment including
paresthesia and hyperesthesia. An estimated 3–10% of all patients with MS have
onset before the age of 18 years. CSF
analysis and MRI are done [4].
The care of children with
MS needs a multidisciplinary team comprising pediatric and adult neurologists,
nurses, physiotherapists, occupational therapists, social workers,
psychologists, and psychiatrists. Demyelination in children is managed with
corticosteroid therapy. Although there are no specific studies of the dose or
effectiveness of corticosteroids, most regimens for severe demyelination use
10–30 mg/kg/dose (to a maximum of 1000 mg/dose) of methylprednisolone by
intravenous infusion for 3-5 days. Immunomodulatory therapies Class I level
evidence for a reduction in the relapse frequency in adults with MS135–139 has
led to the use of interferon beta [5].
MS patients can present
with trigeminal neuralgia (TN) with possible absence of trigger zones and continuous
low intensity pain which should be managed similar to typical TN. Patients may
present with neuropathy of the maxillary (V2) and mandibular branch (V3) of the
trigeminal nerve which may result in burning, tingling or reduced sensation.
Neuropathy of the mental nerve can cause numbness of the lower lip and chin.
Facial weakness and paralysis may be seen in MS patient. Dysarthria may be seen
as scanning speech in these patients. Elective dental treatment should be
avoided in MS patients during acute exacerbation. These patients may require
dental treatment in operating room under general anesthesia. Patient’s
relatives or nurse should be appraised about the importance of daily home care
of oral hygiene [4].
Guillain-Barre
syndrome (GBS) is an immune-mediated disorder of the peripheral nervous system
which is triggered by either infectious or noninfectious factors. The disease
is often triggered by an infectious process, and it affects children of all
ages. GBS is a predominant cause of acute flaccid paralysis which may occur at
any age. The predominant complaint of the pediatric GBS includes weakness of
the limbs, paresthesia, and pain. Autonomic dysfunctions including fluctuating
blood pressure, tachyarrhythmia and bradyarrhythmia, abnormal sweating,
papillary abnormalities are also common in pediatric GBS. In addition,
respiratory failure requiring mechanical ventilation is a serious short-term
complication of GBS [6]. Intravenous immunoglobulin (IV Ig) (0.4g/kg/d, for 5
consecutive days) is a first-line option for adult patients with GBS due to its
safety and convenience. Intravenous corticosteroids as an add-on therapy may be
administrated [7].
Epilepsy
is a disorder that causes seizures or convulsions due to abnormal activity of
brain cells, called neurons. The disorder may be caused by head injury, trauma,
brain tumors or infections, such as meningitis or encephalitis. Conditions at
birth or before birth also may lead to epilepsy, including an insufficient
supply of oxygen to the brain, bleeding in the brain or abnormal blood vessels.
Seizures
can be partial or generalized type. Grand
mal is the most common type of seizure which can occur alone or with other
types. Petit mal (absence seizures) occur exclusively in children and
frequently disappear during second decade of life. Complete neurologic
examination is essential which includes the testing of cranial nerve function,
assessment of mental status and testing of motor function. Blood studies like
complete blood count, electrolytes, glucose, magnesium, calcium are done to
identify any metabolic cause of seizure. All the patients should undergo MRI
and CT scan for detection of any pathology in the brain responsible for
seizures. An EEG (electroencephalogram) is an important tool for classifying
seizure disorder [4].
The first approach in
status epilepticus (SE) should focus on airway management and adequate
ventilation and circulation. It is important to safeguard patients from
injuries caused by uncontrolled movement. It is also important to place the
patient in a lateral position to prevent inhalation, and position a peripheral
venous catheter. Monitoring vital signs (heart rate, blood pressure, oxygen
saturation, and temperature) is essential to evaluate the course of SE. A rapid
blood test should be done to recognize hypoglycemia or poisoning. Benzodiazepines are considered the first choice in
the initial treatment of seizures. Phenobarbital and Phenytoin are considered
second-class drugs to treat seizures. Valproic acid is important in refractory
SE. Propofol is an anesthetic agent with anticonvulsant activity. It is used in
refractory SE [8].
These patients have high
rate of physical injuries, including dental and facial trauma. Hence, precipitation
of seizures during dental treatment should be avoided by reducing psychologic
stress. Inhalation sedation with nitrous oxide (upto 20%) and oxygen is highly
recommended. Phenytoin induced gingival hyperplasia is commonly seen in
anterior labial surfaces of the maxillary and mandibular gingiva. Maintenance
of oral hygiene by chlorhexidine mouthwash can reduce the inflammation or
surgical reduction can be done. Patients taking antiepileptic drugs has marked
bone marrow suppression which causes increased chances of infection and
prolonged bleeding. Hence, a complete blood count should be done prior to any
dental treatment [4].
It is therefore important
for the dentist to familiarize with these neurological manifestations for
better diagnosis and treatment planning in these patients. A close
communication between the dentist and neurologist must be established to find
the best recommendations for the patient and to increase the quality of life of
these patients.