Frontal Lobe Syndrome

What is Frontal Lobe Syndrome?

Frontal lobe syndrome is a condition caused by damage of the frontal lobe. It is characterized by symptoms of personality and behavior deterioration in a previously normal person (also read about Kluver-Bucy syndrome) [1].

Frontal lobe anatomy and physiology

Frontal lobe is the largest lobe of the brain. In humans the frontal lobe is larger and more developed than in any other organism. It is located in the front of the brain. Frontal lobes are involved in:

  • Cognitive functions
    • Problem solving
    • Emotional expression
    • Memory
    • Language
    • Judgement
    • Sexuality
  • Motor functions
    • Conscious moving of the muscles
    • Speech

Frontal Lobe Syndrome

Although both lobes are involved in all behavior, research shows some asymmetrical differences. For example, the left frontal lobe is believed to be more involved in language control, but right frontal lobe plays a bigger role in non-verbal abilities [2].

frontal lobe syndrome anatomy physiology


Frontal lobe is the most common region of the brain where traumatic injury occurs. Besides trauma, other causes for frontal lobe syndrome include:

  • Mental retardation
  • Brain tumors
  • Alzheimer disease (also read about Sundown syndrome)
  • Dementia with Lewy bodies
  • Parkinson-plus syndromes
  • Frontotemporal dementia
  • Cerebrovascular disease
  • Hydrocephalus
  • Schizophrenia
  • Major depression
  • Multiple sclerosis
  • CNS lupus
  • Acute intoxication with recreational drugs and/or alcohol
  • HIV [3]


Frontal lobe syndrome is characterized by a wide variety of symptoms. During examination or surgery it is not always easy to assess these symptoms, but usually the family describes the person as “not how they used to be”. Symptoms of frontal lobe syndrome are:

  • Apathy
  • Abulia-absence of will power
  • Lack of concern
  • Loss of attention
  • Confabulation-production of distorted or fabricated memories
  • Loss of spontaneity
  • Behavior is no longer goal-directed
  • Motor impersistence
  • Restlessness
  • Distractibility
  • Hypomania
  • Inappropriate social behavior
  • Normal memory, but patient can’t “remember to remember”
  • Loss of abstract thought[1,4]



Some authors distinguish 3 separate types of frontal lobe syndrome:

  1. Orbitofrontal syndrome
    • Pseudo-psychopathic behavior- impulsiveness, disinhibition, carelessness, occasional aggressiveness
    • Euphoria
    • Witzelsucht- constant tendency to make jokes, puns
    • Emotional lability
    • Poor sense of judgement
    • Easily distractible personality
  2. Frontal convexity syndrome
    • Indifference towards everything
    • Psycho-motor retardation
    • Loss of self-stimulating, goal-driven personality
    • Motor inconsistency
    • Lack of abstract thought
    • Poor word list generation (for example, when asked to name words that start with letter “a”, patient is not able to do so)
  3. Medial frontal syndrome
    • Spontaneous gesturing
    • Repetition of words
    • Weakness in lower extremities
    • Loss of sensation in lower extremities
    • Incontinence [5]


Patient history

Obtaining thorough patient history is a very important part of making the diagnosis of frontal lobe syndrome. Usually the family member will have some complaint about the patient not being the way they used to be. Notable changes can be:

  • Loss of appropriate behavior, for example, the patient might start to seemingly say everything that comes in their mind, despite their opinion being inappropriate. Also read about Asperger’s syndrome.
  • Loss of table manners
  • Lack of empathy towards other or inability to understand mental status of others
  • Apathy, lack of interest in previous hobbies, interests and people
  • Increase or decrease in sexual interest and lack of judgment about possible sexual partners

When examining the patient information about previous diseases and other health issues should be obtained. Also careful history about head trauma, social history, physical abuse and substance abuse should be obtained. In some cases a psychological stressor, like the death of family member can cause this disorder [6].

Physical examination

The following tests are quite specific to damage of the frontal lobe:

  • Go/no-go test: the patient is instructed to hold up one finger, if the examiner is holding up two and hold up two fingers if the examiner is holding up one. Failure to respond correctly means that the patient lacks normal response inhibition.
  • Visual grasp test: the patient is asked to move their eyes contralateral to the stimulus. If the stimulus is on the right side, patients eyes should move to the left side.
  • Trail making test. The test consists of two parts. In first part the patient is asked to connect 25 numbered circles. In the second part they are asked to connect number from 1 to 13 to letters from A to M in an alternating progression (1-A; 13-M). Total score is the sum of time required to complete each part of the test.
  • Word generation test- patient is asked to generate as many words as they can, for example, starting with the letter B, in one minute. Normal score is at least 8 words.
  • Applause test- patient is asked to clap 3 times after a demonstration by the examiner. Abnormal response is clapping more than 4 times.

Other signs that are not specific, but can be found in frontal lobe syndrome are:

  • Aphasia-inability to formulate or understand language
  • Neglect
  • Memory deficit
  • Lack of judgment, insight, social appropriateness, originality
  • Frontal release responses- suck, grasp, snout reflexes
  • Utilization behavior-using or touching an object that can be considered inappropriate
  • Alien hand syndrome- patient doesn’t control the movements of their hand.
  • Gait impairment
  • Incontinence (see Overactive bladder syndrome)[6]

Laboratory studies

Some laboratory studies might help in finding the underlying cause:

  • Vitamin B12 levels (low levels can be caused by Short bowel syndrome)
  • HIV test
  • Syphilis serology test
  • Thyroid function tests [6]

Imaging studies

CT scanning is the method of choice for diagnosing traumatic injury and brain bleeds as well as hydrocephalus. MRI studies are more sensitive in diagnosing tumors, brain tissue atrophy, subdural hematoma and vascular pathology [6].

Frontal Lobe Syndrome CT Scan

Other tests

Electro encephalography is indicated in case seizure activity is suspected, especially when the patient’s condition is rapidly progressing.

Lumbar puncture is indicated if infection is suspected [6].


The treatment of frontal lobe syndrome depends on the underlying condition. Usually speech, occupational and physical therapies are used. Patient and their family have to be educated about the condition. Patient’s environment will require modulation to reduce the factors that influence their behavior. Most patients require supervision due to lack of impulse control and ability to follow a plan. Medications can be used to control psychoactive behavior. Ritalin has been suggested as a possible drug to treat some of the symptoms of frontal lobe syndrome [6,7].


The prognosis depends on the underlying cause. Usually the changes are not reversible and the quality of life depends on the care patient is receiving [1].

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