白袍恐懼症

Brain tumor clinical presentation

Generalized: Headache, Seizure, Nausea and vomiting, Syncope, Cognitive dysfunction

Focal: Weakness, Sensory loss, Aphasia, Visual spatial dysfunction

<Generalized>

1.    Headaches

dull and constant, but occasionally throbbing.

Localize type: bifrontal, but worse on the same side as the tumor.

Generalize type: result from increased intracranial pressure (ICP),

IICP triad: headache, nausea, and papilledema.

Tumor-related headaches tend to be worse at night and may awaken the patient. (睡覺時血中CO2上升，造成腦血管擴張，因而使腦壓上升，造成頭痛。平躺降低venous return也會使腦壓上升。)

2.    Seizures

the most common symptoms of gliomas and cerebral metastases.

incidence: primary> metastatic lesions

severe: metastatic lesions> primary

routine prophylaxis with anticonvulsant medications is not recommended.

If focal seizures, the clinical presentation is dependent upon the tumor location.

Tumor-related seizures are typically repetitive and are stereotyped.

For patients with focal seizures, a postictal paresis (also known as a Todd's paralysis) may be present.

<p.s.> Todd's paralysis: focal weakness in a part of the body after a seizure. It usually subsides completely within 48 hours. Todd's paresis may also affect speech, eye position (gaze), or vision.

3.    Nausea and vomiting 

Reason: increasing the ICP at the area postrema(嘔吐中樞) of the medulla.

Characteristics: triggering emesis by an abrupt change in body position. neurogenic nausea and vomiting usually occur in the context of other neurologic symptoms such as headache or focal neurologic deficit.

4.    Syncope

Cerebral perfusion pressure= MAP - ICP.

Reason: A significant rise in ICP can temporarily cut off cerebral perfusion, leading to loss of consciousness. (In the presence of a brain tumor, the baseline ICP may be raised to a level that reduces brain compliance; in this setting, even a further small increase in intracranial fluid volume can result in dramatic elevations in ICP.)

A syncopal episode may simulate a seizure, since patients suffer loss of consciousness and may have a few tonic-clonic jerks. Identification of plateau wave-related episodes of loss of consciousness is critical, since these events identify patients who require urgent corticosteroids and/or neurosurgical intervention to reduce elevated ICP rather than treatment with an anticonvulsant.

5.    Cognitive dysfunction

memory problems and mood or personality change, is common among patients with intracranial malignancy.

Patients often complain of having low energy, fatigue, an urge to sleep, and loss of interest in everyday activities. They may become abulic and show a lack of spontaneity. This pattern of symptoms can be confused with depression.

neuroimaging to rule out a brain tumor in patients without a prior history of depression who experience new onset of depressive symptoms without obvious cause.

<Focal>

1.    Weakness 

Muscle weakness is a common complaint in patients with brain tumors. The manifestations may be subtle, particularly in the early stages.

A key feature of tumor-related muscle weakness is its frequent responsiveness to high-dose dexamethasone, particularly with tumors that are near the motor cortex or its descending fibers.

A response to dexamethasone usually means that the weakness is caused by edema and not by direct tumor involvement. In such a patient, craniotomy can be considered to relieve mass effect and lessen the corticosteroid requirement, even if the patient is not resectable for cure.

2.    Sensory loss

Cortical sensory deficits (eg, graphesthesia or abnormalities in stereognosis) can develop in patients whose tumors invade the primary sensory cortex. These sensory deficits usually do not respect a dermatomal or peripheral nerve distribution.

3.    Aphasia

It is a specific sign of a lesion in the dominant hemisphere (usually left frontal or parietal); in comparison, lesions in the nondominant hemisphere may produce apraxia, which refers to an inability to perform purposeful movements.

Patients who are aphasic may be confused with those who have dementia or other psychiatric disorders such as psychosis or depression.

4.    Visual spatial dysfunction

The visual pathway courses through the brain from the retina and optic chiasm to the occipital poles of the cerebral cortex. Because of its long course through the brain, the visual pathway can be affected by brain tumors that involve any of these areas.

=> retina: papilledema(IICP)

=> Prechiasmatic: 單眼全盲

=> compression optic chiasm: bitemporal hemianopsia

=> Postchiasmatic: 兩眼同側hemianopsia(tumor壓迫的對側視野)