Aphasia is an acquired language disorder where there is total or partial impairment in a language modality, including difficulty in producing or comprehending spoken or written language due to lesions in the language-areas of the brain. Damage to these language areas can be caused by a stroke, traumatic brain injury, or other brain injury. Aphasia may also develop slowly, as in the case of a brain tumor or progressive neurological disease, e.g., Alzheimer's or Parkinson's disease. It may also be caused by a sudden hemorrhagic event within the brain. Certain chronic neurological disorders, such as epilepsy or migraine, can also include transient aphasia as a prodromal or episodic symptom. Aphasia is also listed as a rare side effect of the fentanyl patch, an opioid used to control chronic pain.

Depending on the area and extent of brain damage, someone suffering from aphasia may be able to speak but not write, or vice versa (i.e. agraphia, pure alexia), or display any of a wide variety of other deficiencies in language comprehension and production, such as being able to sing but not speak. Aphasia may co-occur with speech disorders such as Dysarthria or Apraxia of Speech, which also results from brain damage.
When deriving from problems with language processing mechanism, aphasia is labeled Direct Aphasia, whereas Secondary Aphasia results from other preexisting issues such as memory impairments, attention disorders and perceptual problems.

Aphasia is often characterized based on the area of the brain where the damage occurred, notably in Broca or Wernicke's areas.

Broca's Aphasia
Also termed Expressive Aphasia, individuals with this type of aphasia have brain lesions in the medial insular cortex. Broca's Aphasia is characterized by broken speech: Sufferers often have trouble with word retrieval, suffer a loss of function words (i.e. the, in, at, etc.) and display a disturbed word order.

Wernicke's Aphasia
Termed Sensory Aphasia, these aphasiacs suffered lesions in the temporal lobe. These individuals usually have no body weakness, because their brain injury is not near the parts of the brain that control movement.
Working from Wernicke's model of aphasia, Ludwig Lichtheim proposed five other types of aphasia, but these were not tested against real patients until modern imaging made more in depth studies available. They are:

1. Pure word deafness
2. Conduction aphasia
3. Apraxia of speech, which is now considered a separate disorder in itself.
4. Transcortical motor aphasia
5. Transcortical sensory aphasia

The different types of aphasia can be divided into three categories: fluent, non-fluent and "pure" aphasias.

• Fluent aphasias, also called receptive aphasias, are impairments related mostly to the input or reception of language, with difficulties either in auditory verbal comprehension or in the repetition of words, phrases, or sentences spoken by others. Speech is easy and fluent, but there are difficulties related to the output of language as well, such as paraphasia. Examples of fluent aphasias are: Wernicke's aphasia, Transcortical sensory aphasia, Conduction aphasia, Anomic aphasia.

• Nonfluent aphasias, also called expressive aphasias are difficulties in articulating, but in most cases there is relatively good auditory verbal comprehension. Examples of nonfluent aphasias are: Broca's aphasia, Transcortical motor aphasia, Global aphasia

"Pure" aphasias are selective impairments in reading, writing, or the recognition of words. These disorders may be quite selective. For example, a person is able to read but not write, or is able to write but not read. Examples of pure aphasias are: Pure alexia, Agraphia, Pure word deafness.

Apraxia of speech, also known as Verbal Apraxia or Dyspraxia, is a neurological speech disorder in which a person has trouble saying what he or she wants to say correctly and consistently. It is not due to weakness or paralysis of the speech muscles (the muscles of the face, tongue, and lips), but rather because the pathways relaying the message to the articulators are not functioning properly  . The severity of apraxia of speech can range from mild to severe.

The cause or causes of DAS are not yet known. Some scientists believe that DAS is a disorder related to a child’s overall language development. Others believe it is a neurological disorder that affects the brain’s ability to send the proper signals to move the muscles involved in speech. However, brain imaging and other studies have not found evidence of specific brain lesions or differences in brain structure in children with DAS. Children with DAS often have family members who have a history of communication disorders or learning disabilities. This observation and recent research findings suggest that genetic factors may play a role in the disorder.

Symptoms

• Difficulty putting sounds and syllables together in the correct order to form words
• Inconsistent mistakes when speaking. For example, may say a difficult word correctly but then have trouble repeating it, or may be able to say a particular sound one day and have trouble with the same sound the next day.
• Groping for the right sound or word, and may trying to say a word several times before actually saying it correctly
• Incorrect use of “prosody” — that is, the varying rhythms, stresses, and inflections of speech that are used to help express meaning.
• Can understand language much better than they are able to use language to express themselves

Some children with the disorder may also have other problems. These can include other speech problems, such as dysarthria; language problems such as poor vocabulary, incorrect grammar, and difficulty in clearly organizing spoken information; problems with reading, writing, spelling, or math; coordination or “motor-skill” problems; and chewing and swallowing difficulties.

In some cases, people with acquired apraxia of speech recover some or all of their speech abilities on their own. This is called spontaneous recovery. Children with developmental apraxia of speech will not outgrow the problem on their own.

Ataxia refers to a lack of muscle coordination in voluntary movements, such as those required for speech, walking, eye movements and swallowing. It is derived from Greek with “a” meaning without and “taxia” meaning order. It is due to a neurologic impairment, with the cerebellum being affected in most cases.

Ataxia isn’t a primary disorder, but instead is a neurological sign (a symptom observed by the doctor) for an underlying condition where the spinal cord or nerves connecting the cerebellum to the muscles are damaged.

Some conditions that can cause ataxia are:
     -    Stroke                                                                                                -    Cerebral Palsy
    -    Head trauma                                                                                     -    Multiple Sclerosis
    -    Tumor                                                                                                 -    Chicken Pox
    -    Toxic Reaction                                                                                  -    Paraneoplastic Syndromes                                                                    
    -    Transient Ischemic Attack                                                                  Degenerative disorders caused by the immune system in response to cancerous
         Decrease of blood supply to parts of the brain                                tumors. In this case, ataxia can appear months or years before the tumor is
                                                                                                                            diagnosed.
Ataxia can also be genetic, in which case it is inherited from a dominant gene from one parent, or recessive gene from both parents.

Ataxia is classified based on the localization of the injury: 
1.    Cerebellar Ataxia
This type indicates damage to the cerebellum, causing neurological deficits such as dysmetria (overestimating or underestimating distances), dysdiadochokinesia (deficiencies in performing rapid, alternating movements), antagonist hypotonia (lack of muscle tone in the opposite side of the affected hemisphere), dyschronometria (inaccurately estimating elapsed time) and asynergy (loss in movement or speed due to a lack of coordination between muscles, joints, organs or limbs).

2.    Sensory Ataxia
It refers to the inability to sense the position of one’s body parts relative to each other, as well as the amount of strength and effort being used for movements. This lack of perception can be caused by dysfunction in afferent signals from the spinal cord to the brain, or by dysfunction in the cortical areas receiving positional information (thalamus, cerebellum, parietal lobes).

3.    Vestibular Ataxia
The vestibular system, which is responsible for one’s sense of balance and spatial orientation, is affected in vestibular ataxia. It may manifest as an imbalance (slow-onset, chronic bilateral cases) or with noticeable nausea, vomiting and vertigo (acute, unilateral cases). 

Symptoms
    -    Slurred speech
    -    Difficulty swallowing
    -    Unintentional back and forth eye movements
    -    Unstable walk
    -    Tendency to stumble
    -    Difficulty in voluntary fine-motor tasks (holding a spoon, writing, etc.)

Dysphagia refers to the difficulty in swallowing  during any of the stages of swallowing. The word itself is derived from Greek with ‘dys’meaning bad/painful/difficult and ‘phagia’ meaning eating/swallowing. It is caused by a neurological dysfunction in the control of the muscles and structures of swallowing during any of the swallowing stages. 

Etiology:
Dysphagia is not a primary disorder and is  instead secondary to or caused by other diseases of various origin:
    -  Neurologic                                 → Parkinson’s, Traumatic Brain Injury (TBI)
    - Connective Tissue disorders   → scleroderma (disease where connective tissue hardens)
    - Structural abnormalities          → cleft palate
    - Iatrogenic (from a medical treatment received for another disease) → Chemotherapy, Intubation
    - Other                                            → psychogenic

There are two main types of dysphagia based on the localization of the difficulty:

It is a motor speech disorder occurring when the affected individual has trouble controlling or weakness of the muscles of speech production, as in the tongue, lips, throat or lungs. Any of the speech subsystems can be affected (respiration, articulation, phonation, resonance and prosody). Dysarthria is characterized by poor articulation.

Types of Dysarthria
Dysarthrias are categorized based on its symptoms.

• Spastic Dysarthria

         Where the speech muscles are tense and in constant contraction, resulting in the inability to move them. The Vocal folds, muscles of respiration,               and movement of articulators can be affected. Spastic Dysarthria correlates to damage from upper motor neurons. Symptoms include low voice               tone (atonic), floppy hypernasality and emotional mobility, where the patient is unable to control his/her emotions.

• Flacid Dysarthria

          Where the speech muscles show a lack of tone and are in constant relaxation, resulting in the inability to appropriately move them to produce                   speech. It correlated to lower neural damage, in the brainstem and/ or cranial nerves. Symptoms include straining quality in voice, reduced pitch           range/ loudness and hypernasality.

• Ataxic Dysarthria

          Where the speech muscles are vastly unable to coordinate to produce phonation. It is a result of cerebellar damage due to head injury, a history of           alcoholism, Multiple Sclerosis or stroke.

• Hypokinetic Dysarthria

          Characterized by a marked decrease in movement of the articulators. Those suffering from Parkinson's Disease often suffer from ypokinetic                       dysarthria and speak without much movement of their lips, mouth and tongue.

• Mixed Dysarthria

          Where symptoms of more than one type of dysarthria are present.
The majority of dysarthric patients are diagnosed as having 'mixed' dysarthria, as neural damage resulting in dysarthria is rarely contained to one part of the nervous system

Causes
Dysarthria is caused by damage to the brain or nervous system as a result of:

• Traumatic brain injury
• Degenerative diseases (i.e. Parkinson's, ALS, Huntington Disease, Ataxia, etc.)
• Toxic & Metabolic diseases
• Thrombotic or embolic stroke

These events cause lesions in the brain areas participating in executing, planning or regulating motor operations. These can result in dysfunction, or failure of: the motor or somatosensory cortex of the brain, corticobulbar pathways, the cerebellum, basal nuclei (consisting of the putamen, globus pallidus, caudate nucleus, substantia nigra etc.), brain        stem (from which the cranial nerves originate), or the neuro-muscular junction (in diseases such as Myasthenia Gravis) which block the nervous system's ability to activate motor units and effect correct range and strength of movements.    

Treatment
Articulation problems resulting from dysarthria are treated by speech-language pathologists, using a variety of techniques. Techniques used depend on the effect the dysarthria has on control of the articulators. Traditional treatments target the correction of deficits in rate (of articulation), prosody (appropriate emphasis and inflection, affected e.g. by apraxia of speech, right hemisphere brain damage, etc.), intensity (loudness of the voice, affected e.g. in hypokinetic dysarthrias such as in Parkinson's), resonance (ability to alter the vocal tract and resonating spaces for correct speech sounds) and phonation (control of the vocal folds for appropriate voice quality and valving of the airway). These treatments have usually involved exercises to increase strength and control over articulator muscles (which may be flaccid and weak, or overly tight and difficult to move), and using alternate speaking techniques to increase speaker intelligibility (how well someone's speech is understood by peers).

More recent techniques based on the principles of motor learning (PML), such as LSVT (Lee Silverman Voice Treatment) Speech therapy and specifically LSVT may improve voice and speech function in PD. for Parkinson's, aim to retrain speech skills through building new generalised motor programs, and attach great importance to regular practice, through peer/partner support and self-management. Regularity of practice, and when to practice, are the main issues in PML treatments, as they may determine the likelihood of generalization of new motor skills, and therefore how effective a treatment is.

Augmentative and Alternative Communication (AAC) devices that make coping with a dysarthria easier include speech synthesis software and text-based telephones. These allow people who are unintelligible, or may be in the later stages of a progressive illness, continue to be able to communicate without the need for fully intelligible speech.

Dysarthria Treatment for Children
Dysarthria in children is classified as a learning disability. Some cases of dysarthria, as in children are of no known causes. It is a speech motor disorder causing high pitch and tone, mispronunciation of words and fast talking. Children benefit from a speech and language therapist to help them slow down, practice beginning and end sounds of words. It is not genetic. Children sometimes cannot chew properly, thus over stuffing their mouths since there is no sensation of fullness. Early in childhood, some show signs of dysarthria but it takes years to get the correct diagnosis.  Children also do well when introduced to others their age to socialize and "pick up" correct word usage. Dysarthria in children without a genetic or brain disorder are more common than first believed. More research is needed to identify the reason this disorder affects an otherwise healthy child.

Signs and Symptoms
The signs and symptoms fall into six categories:

• Intelligence and learning

Current evidence shows that certain individuals with FXS have difficulties with mathematics, anxiety, attention, and/or executive functions. There is also a decrease in measures of executive cognitive functioning, working memory and information processing speed. The relative weaknesses observed in performance IQ can be partly attributed to slowed motor performance as a result of intention tremor. Children with FXS have an intellectual learning rate which is 2.2 times slower than unaffected children.

From their 40s onward, males with FXS begin developing progressively more severe problems in performing tasks that require the central executive of working memory. Phonological memory (or verbal working memory) deteriorates with age in males, while visual-spatial memory is not found to be directly related to age.

• Physical

Prominent characteristics of the syndrome include an elongated face, large or protruding ears, flat feet, larger testes (macroorchidism), and low muscle tone. Ophthalmologic problems include strabismus (lazy eye). This requires early identification to avoid amblyopia (impaired vision with no discernible damage to the eye or optic nerve).

• Social and emotional

FXS is characterized by social anxiety, including gaze aversion, prolonged time to commence social interaction, and challenges forming peer relationships. A child with FXS is also likely to have hyperactivity, and social deficits. Social anxiety in individuals with FXS is related to challenges with face encoding, the ability to recognize a face previously seen.
Females with FXS show a high frequency of avoidant behavior, mood and habit disorders. Females are notably more withdrawn and depressed compared to normal individuals.

• Speech and language

Perseveration is a common communicative and behavioral characteristic in FXS. Children with FXS may repeat a certain ordinary activity over and over. In speech, the trend is not only in repeating the same phrase but also talking about the same subject continually. Cluttered speech and self-talk are commonly seen. Self-talk includes talking with oneself using different tones and pitches.

• Sensory

Children with fragile X have very short attention spans, are hyperactive, and show hypersensitivity to visual, auditory, tactile, and olfactory stimuli. These children have difficulty in large crowds due to the loud noises and this can lead to tantrums due to hyperarousal. Children with FXS pull away from light touch and can find textures of materials to be irritating. Transitions from one location to another can be difficult for children with FXS. Behavioral therapy can be used to decrease the child’s sensitivity in some cases.

• Disorders commonly associated or sharing features with Fragile X

Some individuals with the fragile X syndrome meet the diagnostic criteria for autism.

Most females who have the syndrome experience symptoms to a lesser degree because of their second X-chromosome; however, they can develop symptoms just as severe as their male counterparts. While full mutation males tend to present with severe intellectual disability, the symptoms of full mutation females run the gamut of minimally affected to severe intellectual disability, which may explain why females are underdiagnosed relative to males.

Inheritance
Fragile X Syndrome is a genetic syndrome linked to the X chromosome. For this reason, women are more likely to be carriers of the syndrome, but can only transmit it to their sons. Males with Fragile X will pass the premutation to all their daughters, as males contribute their X chromosomes to all their daughters. Males never transmit the full mutation. Males with blood full mutations only have sperm premutations, and expansion of the syndrome to full mutation never occurs through paternal transmission.

Treatment
There is no current cure for Fragile X. It is presently treated through behavioral therapy, special education, speech therapy and when necessary treatment of physical abnormalities.  Several medications have been proposed, but none are supported by good evidence. Persons with the fragile X syndrome in their family histories are advised to seek genetic counseling to assess the likelihood of having children who are affected, and how severe any impairments may be in affected descendants.

Visit The National Fragile X Foundation's website for more on the syndrome.

Spina Bifida is a birth defect that involves the incomplete development of the spinal cord or its coverings. The term spina bifida comes from Latin and literally means "split" or "open" spine.

Spina bifida occurs at the end of the first month of pregnancy when the two sides of the embryo's spine fail to join together, leaving an open area. In some cases, the spinal cord or other membranes may push through this opening in the back. The condition usually is detected before a baby is born and treated right away.
The two forms of Spina Bifida are Spina Bifida Occulta (hidden), its mildest form where the spinal cord  is often unaffected and children are most often able to avoid any health problems. Spina Bifida Manifesta consists of two types of spina bifida:

1. Meningocele - when the meninges, the membranes responsible for covering and protecting the brain and spinal cord push through the hole in the vertebrae.
2. Myelomeningocele (also called Cleft Spine) - its most common and most severe form, which occurs when the meninges push through the hole in the back, and the spinal cord also pushes though. Most babies who are born with this type of spina bifida also have hydrocephalus, an accumulation of fluid in and around the brain.

A newborn may have a sac sticking out of the mid to lower back. The doctor cannot see through the sac when shining a light behind it.